I was given the equation: 2sqrt(2)(x+y)^2=7x+9y(adsbygoogle = window.adsbygoogle || []).push({});

I need to then:

a)Use rotation of axes to show that the following equation represents a parabola

b) Find the XY- and xy- coordinates of the vertex and focus

c) Find the equation of the directrix in XY- and xy-coordinates

Formulas provided:

General Equation of a Conic

Ax^2+Bxy+Cy^2+Dx+Ey+F=0

cot2(fi) =A-C/B

x=Xcos(fi)-Ysin(fi)

y=Xsin(fi)+Ycos(fi)

So, I got up to a certain point but now I am unsure as to what I must do.

I solved for fi, which equals 45 degrees

I solved for x and y which is

x= X/sqrt(2) -Y/sqrt(2)

y= X/sqrt(2)+Y/sqrt(2)

I think I should plug it into the original equation to get x^2=4py or y^2=4px?

Then I am just oblivious as to how I should solve for directrix and vertex,focus for XY, and xy

Any help would be appreciated

This section is new to me so I am working on learning the fundamentals of this section and this touches upon all aspects of the section.

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# Homework Help: Rotation of Axes showing parabola

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