Question

Which equation represents y=-x^2+4x-1 in vertex form?

a. y=-(x-2)^2+3
b. y=-(x+2)^2-3
c. y=-(x+2)^2-1
d. y=-(x-2)^2+5

Answer 1

Do you know what vertex form is?

Answer 2

no.. :/

Answer 3

Okay, do you know how to solve for the vertex?

Answer 4

no..sorry

Answer 5

Do you want to learn any of it or do you just want the answer...?

Answer 6

both please

Answer 7

Solving for the vertex is simple
the equation is -x^2+4x-1. You should have learned that this means: a=(-1), b=4 and c=(-1). To solve, you just need to know two formulas: h=\[-b/(2a)\] and k=\[c-b^2/(4a)\]

Answer 8

Make sense so far?

Answer 9

yes

Answer 10

okay, so you plug in the numbers. \[h= -(4)/2(-1)\] that is 2, h=2.
Now you use the formula and find what k equals.

Answer 11

3?

Answer 12

@Bmannn13

Answer 13

Sorry, I caught a really bad lag; you still there?

Answer 14

its fine

Answer 15

Yes, it's 3.

Answer 16

ok

Answer 17

All the algebra is done, so now we are at the easy part. Plug it in. Vertex form is y=a(x-h)^2+k. knowing that, plug all the numbers in and you've got the answer.

Answer 18

ok and what is x?

Answer 19

is this right
k=3
h=2
a=-1

Answer 20

x is a variable, so you just leave it as x; yes, exactly.

Answer 21

ok

Answer 22

ok the answer is a

Answer 23

There you go. You got the answer.

Answer 24

thanks for your help

Answer 25

No problem!