Question

f(x)=sinx-cosx x0=п/4

Answer 1

$f(x)=sinx-cosx \ f'(x)=cosx+sinx \ f'(x_0)=cos frac{ pi }{4} +sin frac{ pi }{4} = frac{ sqrt{2} }{2} +frac{ sqrt{2} }{2} = sqrt{2}$