Let f (x) be an odd function defined on R, and if x is greater than 0, f (x) = 3x + 1, find the analytic expression of F (x)

Let f (x) be an odd function defined on R, and if x is greater than 0, f (x) = 3x + 1, find the analytic expression of F (x)

When f (x) = 3x + 1, x > 0
f(x)=3x-1 x