Answer
$a) 4, b) 3, c) 3$
Work Step by Step
Given: $f(x)= x^2+c$ This implies $f'(x)=2x$
a) $f(0)=0$ and $0=0^2+c \implies c=0$ ; $f(2)=( 2)^2+0=4$
b) $f(1)=0$ and $0=1^2+c \implies c=-1$; $f(2)= (2)^2-1=4-1=3$
c) $f(-2)=3$ and $3=(-2)^2+c \implies c=-1$ ; $f(2)= 2^2-1=4-1=3$