Analyzing 1D Motion of a Particle in a Potential

Logarythmic
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Consider the one dimensional motion of a particle in the potential

V(x)=D(e^{-2ax}-2e^{-ax}).

I'm supposed to obtain the expressions for x as a function of time separately for the cases that the total energy E is positive, zero or negative.

I have used

\frac{1}{2}m\dot{x}^2 + V(x) - E = 0

and got the integral

\int \sqrt{\frac{m}{2(E-V(x))}}dx

to solve.

First, is this a correct method?

Second, how do I solve this integral?
 
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Yes, it looks okay. The same kinda substitution i advised in the thread on turning points would be useful.

Daniel.
 
You guess a solution.
 
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