Question

http://i729.photobucket.com/albums/ww292/akatushi101/A2_Unit8_Exam_53q.gif

What is the equation of the following graph?

Answer 1

The equation of an ellipse is given by\[\frac {(x-h)^2}{a^2} + \frac {(y-k)^2}{b^2} = 1\]In this, the center is (0, -2), so h = 0, k = -2. a is your major (horizontal) radius, b is your minor (vertical) radius. a = 1 and b = 3. So your equation is\[x^2 + \frac {(y+2)^2}{9} = 1\]

Answer 2

http://i729.photobucket.com/albums/ww292/akatushi101/CENTERRR.gif

the center of the graph is 4 and -6?

Answer 3

Does (4, - 6) seem like the center? :P
The right and left radii should be equal at the center. The top and bottom radii should also be equal at the center. In this case, the center is (2, -1). The distance to the right of that point to the side of the circle is 6, which is equal to the distance on the left. Same for top and bottom.