Question

Write the equation of each parabola...
a. with vertex (3,-1) and y-intercept 2
b. with vertex (0,5) passing through (2,9)

Answer 1

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

This is the equation you have to plug in with your unknowns

Answer 2

(h,k) is your vertex so those values are the following

h= 3
k=-1

Answer 3

so it'll be:
2 = a (0-3)^2 - 1
2 = a (-3)^2 -1
2= a (9) -1
2 = a + 8
4 = a?

Answer 4

and the second one will be:

y = a (x+0)^2 + 5
9 = a(2+0)^2 + 5
9 = a(2)^2 + 5
9 = a (4) + 5
9 = a (9)
1 = a?

Answer 5

idk if it's right lol .____.

Answer 6

The -1 doesn't subtract from the 9 because 9 has a coefficient of a so they are not like terms. You add 1 to both sides to get rid of the -1 . Then you divide by 9 to both sides

Answer 7

That's the only mistake I saw but other than that you did very good.

Answer 8

so for the first one, a = 1/3?

Answer 9

Yes a=1/3 for the first one and you did the same mistake on the second one as well.

You can't add the 5 and 4 together so you're going to have to subtract 5 to both sides. Then divide 4 to both sides but you still get the same answer as a=1 so that's weird lol

Answer 10

oh LOL i see :) Thank you so much for your help! you're awesome xD