найти производную функции: 1)y=x в кубе-5х в квадрате+1/х 2)y=x cos x 3)y=x в квадрате/1+x

f(х)\' = ((х^4 - 3х^3)^42)’ = (х^4 - 3х^3)’ * ((х^4 - 3х^3)^42)’ = ((х^4)’ – (3х^3)’) * ((х^4 - 3х^3)^42)’ = (4 * х^3 – 3 * 3 * х^2) * 42 * (х^4 - 3х^3)^41 = 42 * (4х^3 – 9х^2) * (х^4 - 3х^3)^41.

f(х)\' = (cos (2х) – sin (3х))’ = (cos (2х))’ – (sin (3х))’ = (2х)’ * (cos (2х))’ – (3х)’ * (sin (3х))’ = = -2sin (2х) - 3cos (3х).

f(х)\' = ((х + 1) / (х^2 + 1))’ = ((х + 1)’ * (х^2 + 1) - (х + 1) * (х^2 + 1)’) / (х^2 + 1)^2 = (((х)’ + (1)’) * (х^2 + 1) - (х + 1) * ((х^2)’ + (1)’)) / (х^2 + 1)^2 = ((1 + 0) * (х^2 + 1) - (х + 1) * (2х + 0)) / (х^2 + 1)^2 = (х^2 + 1 - 2х^2 - 2х) / (х^2 + 1)^2 = (-х^2 - 2х + 1) / (х^2 + 1)^2.