Question

What are the coordinates of the vertex of the parabola given by the equation: y = x2 - 2x - 2 ?



A. (0, -2)
B. (1, -3)
C. (4, 6)
D. (-2, 6)

Answer 1

@SACAPUNTAS

Answer 2

Oh, this is like the one we just did.
Remember the formula for the vertex? :)

Answer 3

im sorry I don't really remember :/

Answer 4

This literally starts exactly the same as the last question we did. :D
Go look at it again. I'll wait.

Answer 5

the vertex formula is −b/2a

Answer 6

Yes. So start by plugging into that. That gives us the x coordinate of the vertex.
Then you can find y via the equation itself, \(y = x^2 - 2x - 2\)

Answer 7

Oh, I should have asked, you know where the a, b, c, etc. are coming from, right?

Answer 8

no..

Answer 9

Oh! I'm sorry. That makes this a lot less clear.

It's the standard form of the equation: \(ax^2 + bx + c = 0\)
As long as it's in that form there are a lot of useful formulas you can use, and they'll all talk about a, b and c.

So in this case, the equation is \(y = x^2 - 2x - 2\) which means that a = 1, b = -2, and c = -2

Answer 10

hmm is the answer D?

Answer 11

Let's check! \(\frac{-b}{2a} = \frac{-(-2)}{2(1)} = \frac{2}{2} = 1\)
So the x value is 1.
I'm not even going to bother to find y because only one of the choices has an x value of 1.

Answer 12

y is -3 which makes the answer B

Answer 13

Yes. :)

Answer 14

thanks!!