{"id":45,"date":"2025-11-08T14:46:03","date_gmt":"2025-11-08T14:46:03","guid":{"rendered":"https:\/\/potentsky.com\/math\/?page_id=45"},"modified":"2025-11-08T14:46:08","modified_gmt":"2025-11-08T14:46:08","slug":"using-the-lambert-w-function","status":"publish","type":"page","link":"https:\/\/potentsky.com\/math\/using-the-lambert-w-function\/","title":{"rendered":"Using the Lambert W Function"},"content":{"rendered":"\n<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n    <meta charset=\"UTF-8\">\n    <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n    <title>Solving 5^x = 100x &#8211; 175 Using Lambert W Function<\/title>\n    <style>\n        body {\n            font-family: 'Georgia', 'Times New Roman', serif;\n            line-height: 1.8;\n            max-width: 900px;\n            margin: 0 auto;\n            padding: 40px 20px;\n            background: #f9f9f9;\n            color: #333;\n        }\n        \n        .container {\n            background: white;\n            padding: 40px;\n            box-shadow: 0 2px 10px rgba(0,0,0,0.1);\n            border-radius: 8px;\n        }\n        \n        h1 {\n            color: #1a237e;\n            text-align: center;\n            font-size: 28px;\n            margin-bottom: 30px;\n            border-bottom: 3px solid #3f51b5;\n            padding-bottom: 15px;\n        }\n        \n        h2 {\n            color: #283593;\n            font-size: 22px;\n            margin-top: 35px;\n            margin-bottom: 15px;\n            border-left: 5px solid #5c6bc0;\n            padding-left: 15px;\n        }\n        \n        h3 {\n            color: #3949ab;\n            font-size: 18px;\n            margin-top: 25px;\n            margin-bottom: 12px;\n            font-style: italic;\n        }\n        \n        p {\n            margin: 15px 0;\n            text-align: justify;\n        }\n        \n        .equation-block {\n            background: #f5f7fa;\n            border-left: 4px solid #3f51b5;\n            padding: 20px;\n            margin: 20px 0;\n            border-radius: 4px;\n            overflow-x: auto;\n        }\n        \n        .equation {\n            text-align: center;\n            font-size: 20px;\n            margin: 15px 0;\n            font-family: 'Cambria Math', 'Times New Roman', serif;\n        }\n        \n        .inline-math {\n            font-family: 'Cambria Math', 'Times New Roman', serif;\n            font-style: italic;\n        }\n        \n        .fraction {\n            display: inline-flex;\n            flex-direction: column;\n            vertical-align: middle;\n            text-align: center;\n            margin: 0 4px;\n        }\n        \n        .fraction .numerator {\n            border-bottom: 1.5px solid #333;\n            padding: 2px 8px;\n            font-size: 0.95em;\n        }\n        \n        .fraction .denominator {\n            padding: 2px 8px;\n            font-size: 0.95em;\n        }\n        \n        sup {\n            font-size: 0.75em;\n            vertical-align: super;\n        }\n        \n        sub {\n            font-size: 0.75em;\n            vertical-align: sub;\n        }\n        \n        .highlight-box {\n            background: #e8eaf6;\n            border: 2px solid #3f51b5;\n            padding: 20px;\n            margin: 25px 0;\n            border-radius: 6px;\n        }\n        \n        .solution-box {\n            background: #fff9c4;\n            border: 3px solid #fbc02d;\n            padding: 25px;\n            margin: 30px 0;\n            border-radius: 8px;\n            box-shadow: 0 2px 8px rgba(251, 192, 45, 0.3);\n        }\n        \n        .final-answer {\n            background: #c8e6c9;\n            border: 3px solid #4caf50;\n            padding: 30px;\n            margin: 35px 0;\n            border-radius: 8px;\n            text-align: center;\n            font-size: 24px;\n            font-weight: bold;\n            color: #1b5e20;\n        }\n        \n        .check-box {\n            background: #e8f5e9;\n            border-left: 4px solid #4caf50;\n            padding: 15px;\n            margin: 15px 0;\n            border-radius: 4px;\n        }\n        \n        .step-number {\n            display: inline-block;\n            background: #3f51b5;\n            color: white;\n            width: 30px;\n            height: 30px;\n            line-height: 30px;\n            text-align: center;\n            border-radius: 50%;\n            margin-right: 10px;\n            font-weight: bold;\n        }\n        \n        .note {\n            background: #fff3e0;\n            border-left: 4px solid #ff9800;\n            padding: 15px;\n            margin: 20px 0;\n            border-radius: 4px;\n            font-style: italic;\n        }\n        \n        .checkmark {\n            color: #4caf50;\n            font-weight: bold;\n            font-size: 1.2em;\n        }\n        \n        table {\n            width: 100%;\n            margin: 20px 0;\n            border-collapse: collapse;\n        }\n        \n        td {\n            padding: 10px;\n            text-align: center;\n        }\n    <\/style>\n<\/head>\n<body>\n    <div class=\"container\">\n        <h1>Solving 5<sup><i>x<\/i><\/sup> = 100<i>x<\/i> \u2212 175 Using the Lambert W Function<\/h1>\n        \n        <p class=\"note\">\n            <strong>Objective:<\/strong> Solve the equation systematically using the Lambert W method, without guessing solutions.\n        <\/p>\n\n        <h2><span class=\"step-number\">1<\/span>Rewrite the Equation<\/h2>\n        <p>We start with:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                5<sup><i>x<\/i><\/sup> = 100<i>x<\/i> \u2212 175\n            <\/div>\n        <\/div>\n        <p>Using the exponential form 5<sup><i>x<\/i><\/sup> = <i>e<\/i><sup><i>x<\/i> ln 5<\/sup>:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                <i>e<\/i><sup><i>x<\/i> ln 5<\/sup> = 100<i>x<\/i> \u2212 175\n            <\/div>\n        <\/div>\n\n        <h2><span class=\"step-number\">2<\/span>Eliminate the Constant Term in the Linear Part<\/h2>\n        <p>We want the right-hand side to be of the form <i>\u03b1<\/i>(<i>x<\/i> \u2212 <i>\u03b2<\/i>). Factor 100:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                100<i>x<\/i> \u2212 175 = 100<span style=\"display: inline-block; margin: 0 5px;\">(<i>x<\/i> \u2212 <span class=\"fraction\">\n                    <span class=\"numerator\">175<\/span>\n                    <span class=\"denominator\">100<\/span>\n                <\/span>)<\/span> = 100<span style=\"display: inline-block; margin: 0 5px;\">(<i>x<\/i> \u2212 <span class=\"fraction\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span>)<\/span>\n            <\/div>\n        <\/div>\n        <p>So the equation becomes:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                <i>e<\/i><sup><i>x<\/i> ln 5<\/sup> = 100<span style=\"display: inline-block; margin: 0 5px;\">(<i>x<\/i> \u2212 <span class=\"fraction\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span>)<\/span>\n            <\/div>\n        <\/div>\n\n        <h2><span class=\"step-number\">3<\/span>Shift the Variable<\/h2>\n        <p>Let <span class=\"inline-math\"><i>t<\/i> = <i>x<\/i> \u2212 <span class=\"fraction\">\n            <span class=\"numerator\">7<\/span>\n            <span class=\"denominator\">4<\/span>\n        <\/span><\/span>, so <span class=\"inline-math\"><i>x<\/i> = <i>t<\/i> + <span class=\"fraction\">\n            <span class=\"numerator\">7<\/span>\n            <span class=\"denominator\">4<\/span>\n        <\/span><\/span>.<\/p>\n        \n        <p>Substitute into the equation:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                <i>e<\/i><sup>(<i>t<\/i> + <span class=\"fraction\" style=\"font-size: 0.8em;\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span>) ln 5<\/sup> = 100<i>t<\/i>\n            <\/div>\n            <div class=\"equation\">\n                <i>e<\/i><sup><i>t<\/i> ln 5<\/sup> \u00b7 <i>e<\/i><sup><span class=\"fraction\" style=\"font-size: 0.8em;\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> ln 5<\/sup> = 100<i>t<\/i>\n            <\/div>\n            <div class=\"equation\">\n                5<sup><span class=\"fraction\" style=\"font-size: 0.7em;\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span><\/sup> \u00b7 <i>e<\/i><sup><i>t<\/i> ln 5<\/sup> = 100<i>t<\/i>\n            <\/div>\n            <div class=\"equation\">\n                <i>e<\/i><sup><i>t<\/i> ln 5<\/sup> = <span class=\"fraction\">\n                    <span class=\"numerator\">100<\/span>\n                    <span class=\"denominator\">5<sup style=\"font-size: 0.7em;\">7\/4<\/sup><\/span>\n                <\/span><i>t<\/i>\n            <\/div>\n        <\/div>\n        \n        <p>Let <span class=\"inline-math\"><i>k<\/i> = <span class=\"fraction\">\n            <span class=\"numerator\">100<\/span>\n            <span class=\"denominator\">5<sup style=\"font-size: 0.7em;\">7\/4<\/sup><\/span>\n        <\/span><\/span>, so:<\/p>\n        <div class=\"highlight-box\">\n            <div class=\"equation\">\n                <i>e<\/i><sup><i>t<\/i> ln 5<\/sup> = <i>k t<\/i>\n            <\/div>\n        <\/div>\n\n        <h2><span class=\"step-number\">4<\/span>Rearrange into Lambert W Form<\/h2>\n        <p>Divide both sides by <i>k t<\/i> and rearrange:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                1 = <i>k t e<\/i><sup>\u2212<i>t<\/i> ln 5<\/sup>\n            <\/div>\n            <div class=\"equation\">\n                <span class=\"fraction\">\n                    <span class=\"numerator\">1<\/span>\n                    <span class=\"denominator\"><i>k<\/i><\/span>\n                <\/span> = <i>t e<\/i><sup>\u2212<i>t<\/i> ln 5<\/sup>\n            <\/div>\n        <\/div>\n        \n        <p>Multiply both sides by \u2212ln 5:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\"><i>k<\/i><\/span>\n                <\/span> = (\u2212<i>t<\/i> ln 5) <i>e<\/i><sup>\u2212<i>t<\/i> ln 5<\/sup>\n            <\/div>\n        <\/div>\n        \n        <p>Let <i>u<\/i> = \u2212<i>t<\/i> ln 5, then:<\/p>\n        <div class=\"highlight-box\">\n            <div class=\"equation\">\n                \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\"><i>k<\/i><\/span>\n                <\/span> = <i>u e<sup>u<\/sup><\/i>\n            <\/div>\n        <\/div>\n\n        <h2><span class=\"step-number\">5<\/span>Apply Lambert W Function<\/h2>\n        <p>The Lambert W function is defined as the inverse of <i>f<\/i>(<i>w<\/i>) = <i>w e<sup>w<\/sup><\/i>. Therefore:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                <i>u<\/i> = <i>W<\/i><span style=\"display: inline-block; margin: 0 3px;\">(\u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\"><i>k<\/i><\/span>\n                <\/span>)<\/span>\n            <\/div>\n            <div class=\"equation\">\n                <i>t<\/i> = \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">1<\/span>\n                    <span class=\"denominator\">ln 5<\/span>\n                <\/span> \u00b7 <i>W<\/i><span style=\"display: inline-block; margin: 0 3px;\">(\u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\"><i>k<\/i><\/span>\n                <\/span>)<\/span>\n            <\/div>\n        <\/div>\n        \n        <p>Since <i>x<\/i> = <i>t<\/i> + <sup>7<\/sup>\u2044<sub>4<\/sub>:<\/p>\n        <div class=\"highlight-box\">\n            <div class=\"equation\" style=\"font-size: 18px;\">\n                <i>x<\/i> = <span class=\"fraction\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> \u2212 <span class=\"fraction\">\n                    <span class=\"numerator\">1<\/span>\n                    <span class=\"denominator\">ln 5<\/span>\n                <\/span> \u00b7 <i>W<\/i><span style=\"display: inline-block; margin: 0 3px;\">(\u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\"><i>k<\/i><\/span>\n                <\/span>)<\/span>\n            <\/div>\n        <\/div>\n\n        <h2><span class=\"step-number\">6<\/span>Simplify the Constant Inside W<\/h2>\n        <p>Recall <i>k<\/i> = <sup>100<\/sup>\u2044<sub>5<sup>7\/4<\/sup><\/sub>. We need to simplify:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\"><i>k<\/i><\/span>\n                <\/span> = \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5 \u00b7 5<sup style=\"font-size: 0.7em;\">7\/4<\/sup><\/span>\n                    <span class=\"denominator\">100<\/span>\n                <\/span>\n            <\/div>\n        <\/div>\n        \n        <p>Note that 5<sup>7\/4<\/sup> = 5<sup>2\u22121\/4<\/sup> = 25 \u00b7 5<sup>\u22121\/4<\/sup>. Therefore:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                <span class=\"fraction\">\n                    <span class=\"numerator\">ln 5 \u00b7 5<sup style=\"font-size: 0.7em;\">7\/4<\/sup><\/span>\n                    <span class=\"denominator\">100<\/span>\n                <\/span> = <span class=\"fraction\">\n                    <span class=\"numerator\">ln 5 \u00b7 25 \u00b7 5<sup style=\"font-size: 0.7em;\">\u22121\/4<\/sup><\/span>\n                    <span class=\"denominator\">100<\/span>\n                <\/span> = <span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\">4 \u00b7 5<sup style=\"font-size: 0.7em;\">1\/4<\/sup><\/span>\n                <\/span>\n            <\/div>\n        <\/div>\n        \n        <p>Let <span class=\"inline-math\"><i>A<\/i> = <span class=\"fraction\">\n            <span class=\"numerator\">ln 5<\/span>\n            <span class=\"denominator\">4 \u00b7 5<sup style=\"font-size: 0.7em;\">1\/4<\/sup><\/span>\n        <\/span><\/span>. Then:<\/p>\n        <div class=\"highlight-box\">\n            <div class=\"equation\" style=\"font-size: 18px;\">\n                <i>x<\/i> = <span class=\"fraction\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> \u2212 <span class=\"fraction\">\n                    <span class=\"numerator\">1<\/span>\n                    <span class=\"denominator\">ln 5<\/span>\n                <\/span> \u00b7 <i>W<\/i>(\u2212<i>A<\/i>)\n            <\/div>\n        <\/div>\n\n        <h2><span class=\"step-number\">7<\/span>Find W(\u2212A) for Both Real Branches<\/h2>\n        <p>Numerically:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                <i>A<\/i> \u2248 <span class=\"fraction\">\n                    <span class=\"numerator\">1.609438<\/span>\n                    <span class=\"denominator\">4 \u00d7 1.495349<\/span>\n                <\/span> \u2248 <span class=\"fraction\">\n                    <span class=\"numerator\">1.609438<\/span>\n                    <span class=\"denominator\">5.981396<\/span>\n                <\/span> \u2248 0.269\n            <\/div>\n        <\/div>\n        \n        <p>So \u2212<i>A<\/i> \u2248 \u22120.269, which is greater than \u2212<sup>1<\/sup>\u2044<sub><i>e<\/i><\/sub> \u2248 \u22120.3679.<\/p>\n        \n        <div class=\"note\">\n            <strong>Important:<\/strong> Since \u2212<i>A<\/i> > \u2212<sup>1<\/sup>\u2044<sub><i>e<\/i><\/sub>, there are <strong>two real branches<\/strong> of the Lambert W function: <i>W<\/i><sub>0<\/sub> (principal branch) and <i>W<\/i><sub>\u22121<\/sub> (secondary branch).\n        <\/div>\n\n        <h2><span class=\"step-number\">8<\/span>Solve for W(\u2212A) Exactly<\/h2>\n        \n        <p>We need <i>W<\/i>(\u2212<i>A<\/i>) such that:<\/p>\n        <div class=\"equation-block\">\n            <div class=\"equation\">\n                <i>W<\/i>(\u2212<i>A<\/i>) \u00b7 <i>e<\/i><sup><i>W<\/i>(\u2212<i>A<\/i>)<\/sup> = \u2212<i>A<\/i> = \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\">4 \u00b7 5<sup style=\"font-size: 0.7em;\">1\/4<\/sup><\/span>\n                <\/span>\n            <\/div>\n        <\/div>\n\n        <h3>First Branch (W<sub>0<\/sub>):<\/h3>\n        <p>Try <i>W<\/i><sub>0<\/sub>(\u2212<i>A<\/i>) = \u2212<span class=\"fraction\">\n            <span class=\"numerator\">ln 5<\/span>\n            <span class=\"denominator\">4<\/span>\n        <\/span><\/p>\n        \n        <p><strong>Check:<\/strong><\/p>\n        <div class=\"check-box\">\n            <div class=\"equation\">\n                <span style=\"display: inline-block; margin: 0 3px;\">(\u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span>)<\/span> \u00b7 exp<span style=\"display: inline-block; margin: 0 3px;\">(\u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span>)<\/span> = \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> \u00b7 5<sup>\u22121\/4<\/sup>\n            <\/div>\n            <div class=\"equation\">\n                = \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\">4 \u00b7 5<sup style=\"font-size: 0.7em;\">1\/4<\/sup><\/span>\n                <\/span> = \u2212<i>A<\/i> <span class=\"checkmark\">\u2713<\/span>\n            <\/div>\n        <\/div>\n        \n        <p>Therefore: <i>W<\/i><sub>0<\/sub>(\u2212<i>A<\/i>) = \u2212<span class=\"fraction\">\n            <span class=\"numerator\">ln 5<\/span>\n            <span class=\"denominator\">4<\/span>\n        <\/span><\/p>\n        \n        <div class=\"solution-box\">\n            <div class=\"equation\" style=\"font-size: 20px; color: #f57c00;\">\n                <i>x<\/i><sub>1<\/sub> = <span class=\"fraction\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> \u2212 <span class=\"fraction\">\n                    <span class=\"numerator\">1<\/span>\n                    <span class=\"denominator\">ln 5<\/span>\n                <\/span> \u00b7 <span style=\"display: inline-block; margin: 0 5px;\">(\u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span>)<\/span> = <span class=\"fraction\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> + <span class=\"fraction\">\n                    <span class=\"numerator\">1<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> = <span style=\"font-size: 1.3em; color: #d32f2f;\">2<\/span>\n            <\/div>\n        <\/div>\n\n        <h3>Second Branch (W<sub>\u22121<\/sub>):<\/h3>\n        <p>Try <i>W<\/i><sub>\u22121<\/sub>(\u2212<i>A<\/i>) = \u2212<span class=\"fraction\">\n            <span class=\"numerator\">5 ln 5<\/span>\n            <span class=\"denominator\">4<\/span>\n        <\/span><\/p>\n        \n        <p><strong>Check:<\/strong><\/p>\n        <div class=\"check-box\">\n            <div class=\"equation\">\n                <span style=\"display: inline-block; margin: 0 3px;\">(\u2212<span class=\"fraction\">\n                    <span class=\"numerator\">5 ln 5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span>)<\/span> \u00b7 exp<span style=\"display: inline-block; margin: 0 3px;\">(\u2212<span class=\"fraction\">\n                    <span class=\"numerator\">5 ln 5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span>)<\/span> = \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">5 ln 5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> \u00b7 5<sup>\u22125\/4<\/sup>\n            <\/div>\n            <div class=\"equation\">\n                = \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> \u00b7 5 \u00b7 5<sup>\u22125\/4<\/sup> = \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> \u00b7 5<sup>\u22121\/4<\/sup>\n            <\/div>\n            <div class=\"equation\">\n                = \u2212<span class=\"fraction\">\n                    <span class=\"numerator\">ln 5<\/span>\n                    <span class=\"denominator\">4 \u00b7 5<sup style=\"font-size: 0.7em;\">1\/4<\/sup><\/span>\n                <\/span> = \u2212<i>A<\/i> <span class=\"checkmark\">\u2713<\/span>\n            <\/div>\n        <\/div>\n        \n        <p>Therefore: <i>W<\/i><sub>\u22121<\/sub>(\u2212<i>A<\/i>) = \u2212<span class=\"fraction\">\n            <span class=\"numerator\">5 ln 5<\/span>\n            <span class=\"denominator\">4<\/span>\n        <\/span><\/p>\n        \n        <div class=\"solution-box\">\n            <div class=\"equation\" style=\"font-size: 20px; color: #f57c00;\">\n                <i>x<\/i><sub>2<\/sub> = <span class=\"fraction\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> \u2212 <span class=\"fraction\">\n                    <span class=\"numerator\">1<\/span>\n                    <span class=\"denominator\">ln 5<\/span>\n                <\/span> \u00b7 <span style=\"display: inline-block; margin: 0 5px;\">(\u2212<span class=\"fraction\">\n                    <span class=\"numerator\">5 ln 5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span>)<\/span> = <span class=\"fraction\">\n                    <span class=\"numerator\">7<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> + <span class=\"fraction\">\n                    <span class=\"numerator\">5<\/span>\n                    <span class=\"denominator\">4<\/span>\n                <\/span> = <span style=\"font-size: 1.3em; color: #d32f2f;\">3<\/span>\n            <\/div>\n        <\/div>\n\n        <h2><span class=\"step-number\">9<\/span>Final Solutions<\/h2>\n        <div class=\"final-answer\">\n            <i>x<\/i> = 2 &nbsp;&nbsp;and&nbsp;&nbsp; <i>x<\/i> = 3\n        <\/div>\n\n        <h2>Verification<\/h2>\n        <div class=\"highlight-box\">\n            <h3>For <i>x<\/i> = 2:<\/h3>\n            <table>\n                <tr>\n                    <td><strong>Left side:<\/strong><\/td>\n                    <td>5<sup>2<\/sup> = 25<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Right side:<\/strong><\/td>\n                    <td>100(2) \u2212 175 = 200 \u2212 175 = 25<\/td>\n                <\/tr>\n                <tr>\n                    <td colspan=\"2\" style=\"color: #4caf50; font-weight: bold; font-size: 1.2em;\">25 = 25 \u2713<\/td>\n                <\/tr>\n            <\/table>\n            \n            <h3>For <i>x<\/i> = 3:<\/h3>\n            <table>\n                <tr>\n                    <td><strong>Left side:<\/strong><\/td>\n                    <td>5<sup>3<\/sup> = 125<\/td>\n                <\/tr>\n                <tr>\n                    <td><strong>Right side:<\/strong><\/td>\n                    <td>100(3) \u2212 175 = 300 \u2212 175 = 125<\/td>\n                <\/tr>\n                <tr>\n                    <td colspan=\"2\" style=\"color: #4caf50; font-weight: bold; font-size: 1.2em;\">125 = 125 \u2713<\/td>\n                <\/tr>\n            <\/table>\n        <\/div>\n\n        <p style=\"text-align: center; margin-top: 40px; font-style: italic; color: #666;\">\n            This solution demonstrates the power of the Lambert W function in solving transcendental equations that combine exponential and linear terms.\n        <\/p>\n    <\/div>\n<\/body>\n<\/html>\n","protected":false},"excerpt":{"rendered":"<p>Solving 5^x = 100x &#8211; 175 Using Lambert W Function Solving 5x = 100x \u2212 175 Using the Lambert W Function Objective: Solve the equation systematically using the Lambert W method, without guessing solutions. 1Rewrite the Equation We start with: 5x = 100x \u2212 175 Using the exponential form 5x = ex ln 5: ex [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"ocean_post_layout":"","ocean_both_sidebars_style":"","ocean_both_sidebars_content_width":0,"ocean_both_sidebars_sidebars_width":0,"ocean_sidebar":"","ocean_second_sidebar":"","ocean_disable_margins":"enable","ocean_add_body_class":"","ocean_shortcode_before_top_bar":"","ocean_shortcode_after_top_bar":"","ocean_shortcode_before_header":"","ocean_shortcode_after_header":"","ocean_has_shortcode":"","ocean_shortcode_after_title":"","ocean_shortcode_before_footer_widgets":"","ocean_shortcode_after_footer_widgets":"","ocean_shortcode_before_footer_bottom":"","ocean_shortcode_after_footer_bottom":"","ocean_display_top_bar":"default","ocean_display_header":"default","ocean_header_style":"","ocean_center_header_left_menu":"","ocean_custom_header_template":"","ocean_custom_logo":0,"ocean_custom_retina_logo":0,"ocean_custom_logo_max_width":0,"ocean_custom_logo_tablet_max_width":0,"ocean_custom_logo_mobile_max_width":0,"ocean_custom_logo_max_height":0,"ocean_custom_logo_tablet_max_height":0,"ocean_custom_logo_mobile_max_height":0,"ocean_header_custom_menu":"","ocean_menu_typo_font_family":"","ocean_menu_typo_font_subset":"","ocean_menu_typo_font_size":0,"ocean_menu_typo_font_size_tablet":0,"ocean_menu_typo_font_size_mobile":0,"ocean_menu_typo_font_size_unit":"px","ocean_menu_typo_font_weight":"","ocean_menu_typo_font_weight_tablet":"","ocean_menu_typo_font_weight_mobile":"","ocean_menu_typo_transform":"","ocean_menu_typo_transform_tablet":"","ocean_menu_typo_transform_mobile":"","ocean_menu_typo_line_height":0,"ocean_menu_typo_line_height_tablet":0,"ocean_menu_typo_line_height_mobile":0,"ocean_menu_typo_line_height_unit":"","ocean_menu_typo_spacing":0,"ocean_menu_typo_spacing_tablet":0,"ocean_menu_typo_spacing_mobile":0,"ocean_menu_typo_spacing_unit":"","ocean_menu_link_color":"","ocean_menu_link_color_hover":"","ocean_menu_link_color_active":"","ocean_menu_link_background":"","ocean_menu_link_hover_background":"","ocean_menu_link_active_background":"","ocean_menu_social_links_bg":"","ocean_menu_social_hover_links_bg":"","ocean_menu_social_links_color":"","ocean_menu_social_hover_links_color":"","ocean_disable_title":"default","ocean_disable_heading":"default","ocean_post_title":"","ocean_post_subheading":"","ocean_post_title_style":"","ocean_post_title_background_color":"","ocean_post_title_background":0,"ocean_post_title_bg_image_position":"","ocean_post_title_bg_image_attachment":"","ocean_post_title_bg_image_repeat":"","ocean_post_title_bg_image_size":"","ocean_post_title_height":0,"ocean_post_title_bg_overlay":0.5,"ocean_post_title_bg_overlay_color":"","ocean_disable_breadcrumbs":"default","ocean_breadcrumbs_color":"","ocean_breadcrumbs_separator_color":"","ocean_breadcrumbs_links_color":"","ocean_breadcrumbs_links_hover_color":"","ocean_display_footer_widgets":"default","ocean_display_footer_bottom":"default","ocean_custom_footer_template":"","footnotes":""},"class_list":["post-45","page","type-page","status-publish","hentry","entry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.5 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Using the Lambert W Function - Math Lab<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/potentsky.com\/math\/using-the-lambert-w-function\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Using the Lambert W Function - Math Lab\" \/>\n<meta property=\"og:description\" content=\"Solving 5^x = 100x &#8211; 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