Composite function with trig?

Question

Let f (x) = 1/(x^2√(25 + x^2) and g(t) = 5 tan t for 0 < t < π/2 

Find (f º g)(t) and simplify so that there are no radicals in the function. Write your answer in terms of sin(t) and cos(t). 

(f º g)(t) = 

Answer 1

The functions  are