Thread: derivaties of Trigonometric Functions

Here is another one I am stuck on.
5sinx/(1+cosx)
this is what I did:

(1+cosx)d/dx[5sinx]-(5sinx)d/dx[1+cosx]/(1+cosx)^2


([1+cos(x)]*(-5)*cos(x)-[5+sin(x)]*[-sin(x)])/([1+cos(x)]^2)

Where did I go wrong here?

Thank you!
Keith

Originally Posted by keith

5sinx/(1+cosx)

Use the product rule.

Originally Posted by Krizalid

Use the product rule.

I looked over the problem and noticed it should have been:
(1+cosx)(5cosx) not -(5cosx)
Thanx anyway

Originally Posted by keith

(1+cosx)(5cosx)

If you wanna derive this, then just expand

Then apply simple rules of derivation.