Question

What is the value of a in this circle's general form? I can find missing values a lot easier when circle's are in standard form, but some help with this would be great!

Answer 1

8

Answer 2

The center of the circle is (-4,2) and in standard form the circle is given by the equation\[(x+4)^2+(y-2)^2=2^2\]

Answer 3

Oh okay! Thank you for putting it into standard form

Answer 4

Also, do you know how to fin the eccentricity of an ellipse?

Answer 5

This one for example

Answer 6

Have you tried finding the ratio c/a

Answer 7

C would be the center right? And would A be a point on the circle?

Answer 8

Is it \[\frac{ \sqrt{3} }{ 2 }\]

Answer 9

Here is used the formula \[\frac{ (x-h)^2 }{a^2}+\frac{(x-k)^2}{b^2}=1\] and \[eccentricity = \sqrt{\frac{ a^2-b^2 }{ a }}\]