(Calculus)Differentiation and its application

[Jojeti]

Hello! I was wondering if anyone could assist me on a few calculus questions, any help would be appreciated, thanks

Determine the differentials of the following functions and calculate the gradient at the given point:
a) y= x2-2+ 1/x2 (x= -2)
b) y= 2ex+3x2+2 (x= 0)
c) y= sin2x + tanx (x= 45̊)