evaluate-fxfprimeleftxright-at-x4xfracpi4-if-fxcosxfleftxrightcos-x

Question

Evaluate $f^{'} (x)$ at $x = \frac{π}{4}$ if $f (x) = \cos x$ .

Accepted Answer

$- \frac{\sqrt{2}}{2}$

Answer

$- \frac{\sqrt{2}}{2}$

Answer

$- \frac{\sqrt{2}}{2}$

Answer

$- \frac{\sqrt{2}}{2}$

Evaluate f′(x)f^{\prime}\left(x\right) at x=π4x=\frac{\pi}{4} if f(x)=cosxf\left(x\right)=\cos x.