F(x) = x^2 sin x

F'(x)

y= tan x/x^2
y'=

F = x^2 sinx

use the product rule to get
F' = 2x sinx + x^2 cosx

F = tanx/x^2
use quotient rule to get
F' = (x^2 sec^2 x - 2x tanx)/x^4
= (x sec^2 x - 2tanx)/x^3

or, writing F as
F = x^-2 tanx
use the product rule to get
F' = -2x^-3 tanx + x^-2 sec^2 x
= x^-3 (-2tanx + x sec^2 x)