Question

Alright, I need somebody to walk me through this.

Rewrite the equation in vertex form. Name the vertex and y-intercept.
y = x2 – 10x + 15

I VAGUELY understand the concept... But I could really use some direction.

Answer 1

Do you know how to complete the square?

Answer 2

I think so... one second...

Answer 3

okay, I have (x=5)^2=10.
Is that right so far?

Answer 4

Is it (x-5)^2=10?

Answer 5

oh I meant a + but could it be either one?

Answer 6

It should be a minus...

y=x^2-10x+25-25+15
y=(x-5)^2-25+15
y=(x-5)^2-10

Answer 7

\[x + 5 =\sqrt{10}\]
is that correct?

Answer 8

No you stop when you have the vertex form

y=a(x-h)^2+k

Answer 9

Idk what vertex form is. :P
okay so... y=(x-5)^2-10 is the final vertex form answer?

Answer 10

Yes that is vertex form.

its in the form y=a(x-h)^2+k where (h,k) is the vertex

so what would the vertex be?

Answer 11

x=5
y=-10

Answer 12

So vertex is (5,-10)

And to find the y intercept you just input 0 into the equation for x and solve for y

Answer 13

so y-intercept would be (0,15) ? :D

Answer 14

Yep

Answer 15

Awesome! That is not as hard as I was making it! Thank you!

Answer 16

You're welcome :)

Answer 17

@CalebBeavers
What do I do if there is a fraction in front of my x^2?