Two phase decay equation solution

[sherif1980]

Hello,

Does anyone know how to solve an equation of the form:

e^-ax+e^-bx=c

Where a,b and c are constants?

This left side of the equation represents the sum of two exponential decay processes, one fast and one slow. I want to know for what positive value of x the expression on the left side of the equation will decay to the constant c.

Thanks!

Sherif

 

[daveb]

Normally, if you have two separate decay processes occurring at the same time, you don't add the expression. Instead, you add the exponents.