+130516 If f(x) = x^2 and g(x) = 3x – 5, find (f ° g)(x)
The notation is a fancy way of saying that we're "plugging" the function "g" into the function "f" and then evaluating what we have......so.....
f(x) = [x]^2 and we're substituting 3x - 5 for x ......so we have.....
f( 3x - 5) = [3x - 5]^2 = [3x -5] [3x -5] = 9x^2 - 30x + 25
This is often confusing.... [I know it was for me].....but think about this.....if I wanted to know what f(2) was, I would evaluate
f(2) = (2)^2 = 4
Here......we're just doing the same thing with a function, rather than a number.....
