Question

If f(x) = x^2 - 1, find f(3).

5

2

8

-2

Answer 1

f(3) is short hand for : everywhere you see x, replace it with a 3 in
x^2 -1

if you change the x into a 3, what do you get ?

Answer 2

wait why replace x with 3?

Answer 3

f(3)= 3x^2

Answer 4

f(x) = x^2 - 1

change the x into a 3. If you do that , you can't get f(3)= 3x^2 because the x is not there.

Answer 5

wait why replace x with 3? Because that is what f(3) means. you start with
f(x) = x^2 - 1

f(3) is "code" for replace (change) the x to a 3
if you have a pencil and paper you would write down x^2 -1, erase the x, and put a 3 in its place

Answer 6

f(3) = 3^2-1

Answer 7

yes, now do the arithmetic. remember that 3^2 is short for 3*3

Answer 8

f(3)= 9-1

Answer 9

yes, and 9-1 is ?

Answer 10

8
thanks i get it