Question

f(x)= 2x+1, g(x)= X^2 - 1

what is (gog)(x)?

Answer 1

g of g of x ?

That means "wherever you see an 'x" in g of x, insert "x^2 +1".

So \(g \, o \, g(x) = (x^2+1)^2 +1\)

Answer 2

Ok, thanks

Answer 3

Here is a really good video on function composition
http://www.youtube.com/watch?v=S4AEZElTPDo (finding f of g and g of f and etc etc.)