Question

Найдите производную функции f(x)=x tg(x) и f(x0), если x0=п/4

Answer 1

f(x0)=π/4*tgπ/4=π/4*1=π/4
f`(x)=tgx+x/cos²x
f`(π/4)=1+π/4:1/2=1+π/2