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Date: 04/13/97 at 17:23:14
From: Nikita Bacchus
Subject: Equation
Hi Dr. Math,

Solve for x in the following equation:

  a) 4 4^(2x+4)-4 = e

  b) arcsin (x+Pi/2) = 3Pi/2.

In the first one, you would use natural logs, right?
Second I'm not sure.


Date: 04/14/97 at 10:20:03
From: Doctor Anthony
Subject: Re: Equation

>  a) 4 4^(2x+4)-4 = e

      4^(2x+4) = (e+4)/4
   (2x+4)ln(4) = ln[(e+4)/4]
          2x+4 = ln[(e+4)/4)]/ln(4)
               = 0.37405
            2x = -3.62595
             x = -1.812977.

>  b) arcsin (x+Pi/2)=3Pi/2

   sin^(-1)(x+pi/2) = 3pi/2
   x+pi/2 = sin(3pi/2) = -1
   x = -pi/2 -1
     = -2.570796.

-Doctor Anthony,  The Math Forum
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Associated Topics:
High School Calculus

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