functions

A function f(x) is a polynomial function in sin^-1x
( ie f(x) = a(sin^-1x )ⁿ + b(sin^-1x )^n-1 + c(sin^-1x )^n-2..........+ k)

the conditions given on f(x) are:
1. f(x) is an onto function.
2. f o f o f o f o f o f o...........o f o f(x) (10 times) = (sin^-1x)¹⁰ⁿ (where n = degree of function in sin^-1x)

find the range of f(x)