1 8
2 9
3 10
We’re going to talk about more ways to use those charts in a bit, but for now,
let’s create a more complex function.
f(x) = 3x – 5Pick a random number—let’s say 3. So what is f (3)? Simple, replace the x
with a 3, and we get 3 (3) – 5, or 4. So far, so good. But a trickier SAT question
might ask for f (4c + 2). In this case, we have to replace x not with a number, but
with an algebraic expression, like this:
As if that wasn’t fun enough, we can also combine functions.The trick is to first run 6 through the inside function g, then run that answer
through the outside function f.
Surely that’s all the frim-frammery that the SAT can pull with functions,
right? Oh no, my friend, there is one last bit of frim-fram. We can also put a
function within an expression.
Remember: f(x)=y. y is a variable. Use substitution.