help pleeez

i have only 10 min

Given the underneath fragment code that is written in C language, Write down the function with domain and codomain then prove that function is bijective (One to one and Onto) if codomain excludes {5}? Find the inverse of that function? SHOW ALL YOUR WORKS double fun(double n){ if((int)n!=2) return (5*n+1)/(n-2); }