Question

I'm stuck with this one ;c. Please help.

Suppose a parabola has vertex (5,-3) and also passes through the point (6,1). Write the equation of the parabola in vertex form.
A. Y=(x-5)^2-3
B. Y=4(x-5)^2-3
C. Y=4(x+5)^2-3
D. Y=4(x-5)^2+3

Answer 1

Well first use the vertex... (5, -3) means
y=a(x - 5) - 3

now use the point (6, 1) - plug in x=6 and y=1, and find a.

Answer 2

Now I know it's either A or B.

I haven't learned how to find a, but i think a equals four?

Answer 3

y=a(x - 5) - 3

now use the point (6, 1) - plug in x=6 and y=1, and find a...

1=a(6 - 5) - 3

^find a

Answer 4

a is 1, that means the correct answer is A.

Answer 5

cuz 6-5 is 1. then multiply a by one, you get a, or 1. Am i right?

Answer 6

no... you have to SOLVE for a.

1=a(6 - 5) - 3
6-5 is 1, so it becomes
1=a - 3

Answer 7

but that's not from my choices..

Answer 8

I know you can solve that for a... try it.

Answer 9

just tell me what's a-3. lol

Answer 10

haha i know you can do it ;)

1=a - 3

try adding 3 to both sides.

Answer 11

ohhhh ohh it's 4. !!

Answer 12

it's either 4, or 0. lol

Answer 13

Its four haha :) good job, i knew you could do it.

Answer 14

Yay! You'll be a great teacher, cuz you help figure it out before telling them the answer. Thank you very much agent Smith!

Answer 15

unless you're already a teacher, lol

Answer 16

Thanks... I am already a teacher :D

I teach algebra 2, and also precalculus/trigonometry, and also physics. And also AP physics!

Answer 17

That's an amazing, wish you luck with you're teaching.(:

Answer 18

*your

Answer 19

Thanks! :D my students seem to like me!