Question

f(x)=$e^{-x} cosx$

calculati derivata functiei

VA ROG!!

Answer 1

$f'(x)=e^{-x}\cdot (\cos x)' + (e^{-x})^{'} \cdot \cos x=\\=-e^{-x}\cdot \sin x-e^{-x}\cdot \cos x=-e^{-x}(\sin x+\cos x)$