# Finding roots of an exponential function

• Oct 19th 2008, 03:13 PM
skyslimit
Finding roots of an exponential function
Hello,

In this problem i must take the drivite of $f(x) = x^2*e^x$,

which i gather is $2xe^x+x^2e^x$

Next I must set f(X) to zero. However, I do knpow how to solve for roots on this function. Any help?
• Oct 19th 2008, 03:39 PM
Chris L T521
Quote:

Originally Posted by skyslimit
Hello,

In this problem i must take the drivite of $f(x) = x^2*e^x$,

which i gather is $2xe^x+x^2e^x$

Next I must set f(X) to zero. However, I do knpow how to solve for roots on this function. Any help?

In solving $2xe^x+x^2e^x=0$, take note that $e^x\neq0~\forall x\in\mathbb{R}$

So divide both sides by $e^x$, and we're left with $2x+x^2=0$

I'm sure you can take it from here.

--Chris