Intro to Calculus homework help!!

[sanmina83]

The problem involves the function:

E(c) = (c-f(x))^2dx, from x=0 to x=3

The function f(x) is not specified, but:

f(x)dx = 7, from x=0 to x=3 and f(x))^dx= 14, from x=0 to x=3

a) Find E(5)
b) Find the value of c that makes E(c) a minimum. Prove this is a minimum.

*If someone could help me with this problem, I would really appreciate it!