1. second derivative

y = e^xsinx

y'' = e^xcosx - e^xsinx

correct? much appreciated.

2. maybe not..

what is your first derivative?

3. Originally Posted by kalagota
maybe not..

what is your first derivative?
the first derivative is

y' = e^xsinx + e^xcosx

4. Originally Posted by jvignacio
the first derivative is

y' = e^xsinx + e^xcosx
Correct, and what is the second derivative? (Note your answer in your first post is not correct.)

5. Originally Posted by Chop Suey
Correct, and what is the second derivative? (Note your answer in your first post is not correct.)

hmm is it.

y'' = (e^xsinx + e^xcosx) + (e^xcosx - e^xsinx) ??

6. yes indeed!

and you should see that the terms with sin x cancel..

7. Originally Posted by kalagota
yes indeed!

and you should see that the terms with sin x cancel..
so it leaves e^xcosx + e^xcosx ??

8. yes.. or simply $2e^x\cos x$