Question

The equation y^2+8y−x+18=0 represents a parabola. Drag and drop the expressions into the boxes in the equation to rewrite the equation of this parabola in standard form.
x= ( )^2 + ___

Answer 1

Answer:

The equation of parabola is standard form is $x=\left(y+4\right)^2+2$

Step-by-step explanation:

Given equation of parabola is,

$y^2+8y-x+18=0$

In order to find the equation of parabola in standard form, eliminate x from left side of equation and use completing square method to find the equation.

First step is to add x on both side of equation.

$y^2+8y-x+18+x=0+x$

$y^2+8y+18=x$

Rewriting,

$x=y^2+8y+18$

Now applying completing square method as follows.

Following are the steps for calculation of this method.

Find the last term of above equation by using below formula,

$Last\:term\:of\:square=\left(\dfrac{coefficient\:of\:y}{2}\right)^{2}$

Now coefficient of y is 8.

$\therefore Last\:term\:of\:square=\left(\dfrac{8}{2}\right)^{2}$

Simplifying,

$Last\:term\:of\:square=\left(4\right)^{2}$

$Last\:term\:of\:square=16$

Second step is to add and subtract the last term.

$x=y^2+8y+18+16-16$

Rewriting,

$x=y^2+8y+16+18-16$

Since $\left(a+b\right)^{2}=a^{2}+2ab+b^{2}$

Using above formula,

$x=\left(y+4\right)^{2}+2$

Therefore, the equation of parabola in standard form is $x=\left(y+4\right)^{2}+2$