Question 45553
if f(x)= 3x + 1, 
and g(x) = (x^2 + 5x)^-1/2 
find g(f(x)) 

g(f(x))=g(3x+1)
=[(3x+1)^2+5(3x+1)]^(-1/2)

=[(9x^2+6x+1+15x+5]^(-1/2)

=[9x^2+21x+6]^(-1/2)
=[3(3x^2+7x+2)]^(-1/2)

Now you can invert and take the square root but you
only make it a bigger mess.
Cheers,
Stan H.