Question

What is the equation in standard form of a parabola that contains the following points?
(-2, -20) (0, -4) (4, -20)
Please help, explanation would be much appreciated

Answer 1

ok, do you know what kind of equation makes a parabola?

Answer 2

y = a(h-x)^2 + k
where
x and y are points on the parablola [given]
h and k is the vertext point of a parabola [given]
a is a 'multiplier' or a 'scalar' for how wide the parabola spans out [which you'll need to solve for]
make sense so far?

Answer 3

or you can just substittue x and y in a quadratic equation, y=Ax^2 + Bx + C, and use system of equaions

Answer 4

Okay, I think I get it so far

Answer 5

whose method do you wanna use?

Answer 6

We can use yours

Answer 7

:( haha ^_^

Answer 8

HAHA^

so can you substitute x and y in that equation i gave you. i'll start with the first one. you try the other two

-20= A(-2)^2 + B(-2) + C

Answer 9

-4 = a(0)^2 + b(0) + c ??

Answer 10

yes. and the last one?

Answer 11

-20 = a(4) + b(4) + c

Answer 12

ok, do you see that these are the 3 equations we came up with?