I stumbled upon this question in my text book :
Let f and g be polynomials defined by f(x)=x-1 and g(x)=x^2 -1.
Find formulas for f o g and g o f.
I dont fully understand what they mean by finding a formula.
so we no fog = (x^2-1)-1 = x^2-2
and gof =(x-1)^2 -1= x^2-2x
Soo how exactaly do we find a formula?