Math Is Fun Forum

yehoram

Member

Registered: 2010-06-24

Posts: 8

Exponential equation

How can I deal with this equation ??

Last edited by yehoram (2010-07-29 07:38:42)

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Exponential equation

Hi;

You can take it down to wolfram alpha and they can solve it for you. To do it by yourself is a course in  Numercal Analysis. Always difficult to locate and isolate the roots of non linear equations. To get the the real roots, start by graphing the equation.

http://www.mathsisfun.com/graph/functio … 9999999999

Suggests a positve root at 6. This you can verify easily. Going to be a little difficult proving that is the only real root. There are complex roots.

We can also manipulate the problem which will get a real root but not the complex ones.

Solve for x, it is just a linear equation so you should have no problem.

x= 6 is one answer.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,298

Re: Exponential equation

Hi Yehoram

Put all '3 to the power' terms on one side and '2 to the power' on the other.

Factorise 3^x and the bracket is a number.  Similarly with 2^x.

Make (3/2)^x the subject and take logs.

Hope that helps

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

soroban

Member

Registered: 2007-03-09

Posts: 452

Re: Exponential equation

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