Question

Which of the following represents the graph of f(x) = 3x2 - 12 ?

Answer 1

@Michele_Laino

Answer 2

from your equation, I get:
\(f(0)=-12\), so the correct graph has to pass at point \((0,-12)\)

Answer 3

what are your options, please?

Answer 4

There are 3 that do..

Answer 5

more precisely, the equation \(f(x)=3x^2-12\), is a parabola, which is concave up

Answer 6

The first one lands on -2 and 2

Answer 7

The next one lands on -3 and 3

Answer 8

And the last one lands on -4 and 4

Answer 9

If I replace \(x=2\) I get:
\(f(2)=3 \cdot 2^2-12=...?\)

Answer 10

please complete that computation

Answer 11

0?

Answer 12

3x4 is 12 - 12 is 0.

Answer 13

correct!
Similarly, if I rplace \(x=-2\), I get:
\(f(-2)=3 \cdot (-2)^2-12=...?\)

Answer 14

replace*

Answer 15

Wouldn't that be 0 too?

Answer 16

correct!

Answer 17

So how do I figure out which graph is right?

Answer 18

so, summarizing, we have these 3 conditions:
1) the parabola passes at point \((0,-12)\)
2) the parabola passes at point \((2,0)\)
3) the parabola passes at point \((-2,0)\)