Parabola General to standard form

AI Thread Summary
The equation x^2 - 4x + 8y + 12 = 0 is rewritten in standard form as (x-2)^2 = -8(y-8). The vertex of the parabola is located at the point (2, 8). The focus can be determined using the formula 1/4a, where a is derived from the equation. The discussion clarifies that the parabola opens downward, resembling an upside-down 'U'. Understanding these transformations is essential for graphing the parabola accurately.
markwjak
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Homework Statement


write the standard form of the equation
x^2-4x+8y+12=0
find the focus

Homework Equations


The Attempt at a Solution


i have it down to (x-2)^2=-8(y-8)
i'm not sure if you have to multiply the -8 on the right side of the equations by 4 since the focus is 1/4a
 
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markwjak said:

Homework Statement


write the standard form of the equation
x^2-4x+8y+12=0
find the focus

Homework Equations





The Attempt at a Solution


i have it down to (x-2)^2=-8(y-8)
i'm not sure if you have to multiply the -8 on the right side of the equations by 4 since the focus is 1/4a

(x-2)^2=-8(y-8)

let x' = x-2
let y' = y-8

So, x^2 = -8y'
or y' = -(1/8)*x^2

This is it in standard form. To plot it, the vertex of the parabola will be (2, 8) and it will look like an upside down 'U'.
 
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