identify if the given functions are one to one
1. f(x)=x^3-7x
2. g(x) = square root x-3+1
3. h(x)=4x^4-2x^2+11
all odd functions are 1:1, since f(-x) = -f(x)
square roots are 1:1 on the defined domain.
h(x) is an even function, so f(-x) = f(x) and it cannot be 1:1.