My math teacher has been out for 2 days and the subs have just been putting notes up and I'm totally not getting this. So maybe someone here can explain everything in other ways. Note that my book does a crappy job of explaining this subject. But it does break it down into two distince areas - Ellipses Centered at (0,0) and Ellipses Centered at (h,k).(adsbygoogle = window.adsbygoogle || []).push({});

Ellipses Centered at (0,0)

According to my book, there are 6 points that make up an ellipses. V and V' are the vertices of the ellipse where V has the coordinates (a,0) and V' has the coordinates (-a,0). The points m and m' represent the points on the minor axis of the array and have the coordinates (0,b) and (0,-b) respectivally. The ellipse also has two foci (F and F') located at (c,0) and (-c,0). The value "a" represents the distance from the center of the array to the vertex on the major axis. The value "b" is the distance from the center to the vertex on the minor axis. The value "c" represents the distance from the center to the focus.

The book also goes on to give the equation of an ellipse is (x^2/a^2) + (y^2/b^2) = 1 and gives the formula a^2 = b^2 + c^2 for finding the value of c (which turns into c^2 = abs(a^2 - b^2)).

The book goes on to say that you must set up the formulas such that a^2 > b^2. But that doesn't make any sense. I try to plug everything in for an ellipse that I know has a major axis on the y axis (meaning it is vertical) yet when I graph it, it looks like it's horizontal (its major axis was on the x axis).

So can someone explain a universal method for solving problems involving ellipses centered at (0,0)?

Ellipses Centered at (h,k)

Most of the questions that I had for ellipses centered at (0,0) apply here, but I have some more questions.

Exactly what do these steps mean:

(1) collext x terms/y terms on one side

(2) get constant on the other side

(3) complete the square

(4) factor

(5) divide to get a constant of 1

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# PreCalc - Ellipses

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