Ok here are some examples that I am confused with: f(x)=sq.rt.(x+1) Inverse: y=x^2-1, x greater or equal to 0?? f(x)=sq.rt.(x+10) Inverse: y=x^2-10, x greater or equal to 0?? How come you need the "x is greater or equal to 0" after each inverse?Can someone explain to me why this is? Is it because you can only inverse the positive side of the sq.rt.? How come you can't inverse the other side? I just don't get why you need to right that in the answer. Thanks a lot!!