00:01
I don't have a way of showing my graphing calculator, but what you could do is hit like y equals and find your y equals button and type in negative x squared plus.
00:13
So that 4x plus one? but if you're looking at the options, if you have a y intercept, that means x is zero.
00:24
If you plug in a bunch of zeros, you're going to get one.
00:26
So at this point, i would probably imagine you didn't have a calculator and use.
00:31
X equals negative b over 2a well if you've never seen that before then i would tell you to go ahead and use your graph and calculator and negative over negative is positive 4 divided by 2 is 2 so that's where my vertex is going to be and if i plug into infer f of 2 i get the negative of 4 4 times 2 is 8 so you end up with a vertex up to 5 and then the other thing that's nice with parabolas is that's your axis of symmetry.
01:06
So the graph is going up to 2, 5 and has this kind of behavior.
01:12
And the reason why finding that is important, let me see.
01:18
So it looks like the best answer is the top left option...