F(x+4)=F(x), and the function f (x) is a function with a period of 4.

F(x) is odd function, and f(-x)=-f(x).

f(7)= f(3+4)= f(3)= f(- 1+4)= f(- 1)=-f( 1)

The function f(x) is within the definition domain; f(x)=2x^2

f(7)=-f( 1)=-2