Posted by **gnozahs** on Friday, June 5, 2009 at 1:49am.

If f(x)=4sinx/1+cosx

then f'(x)=_____?

I think that the derivative of 4sinx would be 4cos and cosx would be sinx but I don't know where to go from there.

- Calculus -
**MathMate**, Friday, June 5, 2009 at 7:38am
put u=4sin(x), and v=(1+cos(x)),

then use the quotient rule:

d(u/v)= (v du/dx - u dv/dx) / v^{2}

- Calculus -
**MathMate**, Friday, June 5, 2009 at 7:41am
Sorry, I didn't see the comment the first time,

d(cos(x))/dx = -sin(x)

## Answer This Question

## Related Questions

- Calculus - f(x)=4sinx/1+cosx find f'(x) this is what i got and i dunno what i ...
- Trig........ - I need to prove that the following is true. Thanks (cosx / 1-sinx...
- Pre-Calc - Trigonometric Identities Prove: (tanx + secx -1)/(tanx - secx + 1)= ...
- Trigonometry Check - Simplify #3: [cosx-sin(90-x)sinx]/[cosx-cos(180-x)tanx] = [...
- Math - Verify the identity . (cscX-cotX)^2=1-cosX/1+cosX _______ sorry i cant ...
- Precalculus/Trig - I can't seem to prove these trig identities and would really ...
- Calculus - determine the absolute extreme values of the function f(x)=sinx-cosx+...
- trigonometry - can i use factoring to simplify this trig identity? the problem ...
- Trigonometry. - ( tanx/1-cotx )+ (cotx/1-tanx)= (1+secxcscx) Good one! ...
- Calculus 2 Trigonometric Substitution - I'm working this problem: ∫ [1-tan...

More Related Questions