Center and Radius of a Circle - Algebra 2

What is the center and radius of 9x^2 + 4y^2 = 36?

Hi,

9x² + 4y² = 36

This is not a circle because there are different coefficients in front of x² and y². It is an ellipse.

x² . . y²
---- + ---- = 1
4 . . . 9

The center is at (0,0).

The major axis is 3 in the y direction to the endpoints at (0,3) and (0,-3). The minor axis goes 2 in the x direction to (2,0) and (-2,0).

I hope that helps!! :-)

9x^2 + 4y^2 = 36
=> 9x^2/36 + 4y^2/36 = 1 (divide by 36)
=> x^2/4 + y^2/9 = 1
=> (x/2)^2 + (y/3)^2 = 1

This is a equation of an ellipse (not a circle).
Radius? No such thing for an ellipse...
In standard form, the equation is x^2/4 +y^2/9 =1
This is an ellipse with center (0,0).
When x = 0, y = +/- 3. So (0,3) and (0,-3) are vertices.
When y = 0, x = +/- 2. So (2,0) and (-2,0) are vertices.
The major axis is parallel to the y-axis.

I am so slow, I'll never get Best Answer. lol

9x^2 + 4y^2 = 36

is NOT a CIRCLE...

it is an ellipse !

[(x - h)^2]/a^2 + [(y - k)^2]/b^2 = 1

is the equation of an ellipse centered at (h, k)

can you do it now ? Try !

¶

[center: (0, 0)]

It's not a circle, it's an ellipse.

That is an ellipse