Find the inverse of the function f(x) = sqrt{r^2 - x^2}, where 0 < or = to x < or = to r
1) one to one
it means each element of domain will have a unique image in codomain.no two elements of domain can have the same image in codomain.
2) onto
it means each element of codomain will surely have a preimage in the domain.no element of codomain will left unlinked with element of domain.
I hope this helps.if still there is any problem then you may ask it freely.