Could you see if what i have done is right for the following questions:

Ive got to find whether they are injection surjection or bijection for any integer to any integer so z to z (sorry i cant use latex)

1. f(x) = x^3

bijection

2. g(x) = x-3

bijection

3. h(x) = 3x+1

bijection

4. i(x) = (x^2) -1

Surjection