The definition field of odd function f (x) is R. when x > 0, f (x) = - x 2x2, then the expression of F on R

The definition field of odd function f (x) is R. when x > 0, f (x) = - x 2x2, then the expression of F on R

When x = 0,
f(-0)= -f(0)
f(0)= - f(0)
f(0)=0
When X0
f(-x)= - (-x)^2+2x+2
= - x^2+2x+2
Since f (x) is an odd function, f (- x) = - f (x)
-f(x)= - x^2+2x+2
f(x)=x^2-2x-2
` {x^2-2x-2 (x0)