If `f(x)=cosxdotcos2xdotcos4xdotcos8xdotcos16 x ,` then find `f^(prime)(pi/4)dot`

If f(x)=cos x cos2x cos4x cos(8x)*cos16x then find f'((pi)/(4))

If f(x)=cosxcos2xcos4xcos8xcos16x," then "f'((pi)/(4)) is

If f(x)=cos x cos2x cos4x cos8x cos16x then

If f(x)=cos x*cos2x*cos4x*cos8x.cos16x, then f'((pi)/(4)) is :

If f(x)=cos x cos2x cos4x cos8x cos16x then f'((pi)/(4)) equals

If f(x)=|x|^(sin x|), then find f'(-(pi)/(4))

if f(x)=cos x find f'(x) from the first principle and hence find f'((pi)/(4))

f(x)-cos5x+A cos4x+B cos3x+C cos2x+D cos xE and T-f(0)-f((pi)/(5))+f((3 pi)/(5))+......+f((8 pi)/(5))-f((9)/(4) then T