Question

does anyone know how to write y=-2x^2-4x+3 in intercept form using the quadratic formula? :)

Answer 1

you need to find the x intercepts
since the formula for intercept form is
y= a(x-p)(x-k) where
x = p
x =k
are the x-intercepts for your graph

Answer 2

okay makes sense, so if i had an equation already in intercept form like y=(x+2)(x-3) how would I write that in standard form?

Answer 3

oh okay i thought that was vertex form

Answer 4

oh oops wrong one, i mean
standard form is ...
f(x) = ax^2 + bx + c

Answer 5

y = (x+2)(x-3)
you just multiply them to get that

Answer 6

oh okay, yes thats what i have :) i just dont know how to change it into different forms

Answer 7

wait, my alg 2 is rusty, hold on i need to look this up..

Answer 8

would it be x^2-x-6?

Answer 9

ah yes, i was right,
yeah that is your standard form

Answer 10

okay, so how do i write that same equation in vertex form?

Answer 11

-b/2a = x coordinate for your vertex

Answer 12

so x would be 1/2?

Answer 13

Yes, then plug that value in
into your original function
x^2 - x - 6 = y
for the y value of the vertex

Answer 14

(1/2)^2 - 1/2 - 6 = y

Answer 15

so 1/4 - 2/4 - 6 =y
y = -1/4 - 6
y = -25/4

Answer 16

so what would i do now to get the vertex form?

Answer 17

your vertex is (1/2,-25/4)
vertex form is
y = a(x-h)^2 + k
y = (x-1/2)^2 - 25/4

Answer 18

thank you so much!