Given the function f(x)=∫2cos(x)1−t2dtf(x) = \int_{2}^{\cos(x)} \sqrt{1-t^2} dtf(x)=∫2cos(x)1−t2dt, what is the derivative f′(x)f'(x)f′(x) at x=πx = \pix=π?
000
111
−1-1−1
π\piπ