Given f(x)=∫0sinx1−t2dtf(x) = \int_0^{\sin x} \sqrt{1-t^2} dtf(x)=∫0sinx1−t2dt, what is the derivative f′(x)f'(x)f′(x)?
cos2x\cos^2 xcos2x
sin2x\sin^2 xsin2x
∣cosx∣cosx|\cos x| \cos x∣cosx∣cosx
1−cosx1 - \cos x1−cosx