# solving an nonlinear exp equation

• Jun 12th 2011, 11:17 AM
sheikhnir
solving an nonlinear exp equation
in my research work I am sticking with a equation like--
A1*exp(a*x)-A2*exp(-a*x)+A3*exp(-x/A)=0
solving for x
how should i proceed if i don want to solve it numerically..
I mean I need some expression for x. what may be the technique to follow.
• Jun 12th 2011, 02:39 PM
mr fantastic
Quote:

Originally Posted by sheikhnir
in my research work I am sticking with a equation like--
A1*exp(a*x)-A2*exp(-a*x)+A3*exp(-x/A)=0
solving for x
how should i proceed if i don want to solve it numerically..
I mean I need some expression for x. what may be the technique to follow.

In general it cannot be solved analytically, in general it will need to be solved numerically.
• Jun 12th 2011, 02:46 PM
pickslides
You could graph each term separately and find an approximate solution using an addition of ordinates, I don't see this one solved algebraically.
• Jun 13th 2011, 08:00 AM
sheikhnir
well the equation actually has not have only one independent variable actually there are two..
let's see like this A1=f(y)
now,
A1*exp(a*x)-A2*exp(-a*x)+A3*exp(-x/A)=0
is it possible to solve like x=f(y)
like as below

if (y+1)exp(-a*x)=1
then x= -ln(1/(y+1))/a

Thanks to all for helping me to understand
• Jun 13th 2011, 08:04 AM
sheikhnir
actually we cant say it solve, find an expression for x.