How do I solve this f(x) = sinx cosx?

0 ⤊

I need to differentiate.

2006-12-17 07:12:50 · 2 answers · asked by kira 2 in Science & Mathematics ➔ Mathematics

since
sinx cosx = 1/2 sin 2x
then
f(x)=1/2 sin(2x)
f'(x)=1/2 (2) cox(2x)= cos(2x)

Note: cos^2(x)-sin^2(x)=cos(2x) :)

2006-12-17 07:21:30 · answer #1 · answered by ws 2 · 0⤊ 0⤋

Product rule.

(sinx)' = cosx
(cosx)' = -sinx

f'(x) = sinx (cosx)' + (sinx)' cosx
f'(x) = sinx (-sinx) + (cosx) cosx
f'(x) = cosÂ²x - sinÂ²x

2006-12-17 15:16:02 · answer #2 · answered by Jim Burnell 6 · 0⤊ 0⤋