Question

For f(x)=3x and g(x)=x+1(g o f)(x) =?

Answer 1

We have two function

$f(x)=3x$

and

$g(x)=x+1$

We need to find the composition of these function, i.e.

$(g\circ f)(x)$

Now, notice the following diagram

then, we have defined the composition via our diagram, i.e.

$(g\circ f)(x)=g(f(x))$

We need to find first the image of x via f, and then to this image f(x), find the image via g, as follows