Question

Write the equation of a circle with a center at (-2,-10) and a radius of 1.2.

A) (x + 2)2 + (y + 10)2 =1.2
B) (x - 2)2 + (y - 10)2 = 1.2
C) (x + 2)2 + (y + 10)2 = 1.44
D) (x + 2)2 + (y + 10)2 = 14.4

Answer 1

The correct option is the letter "C",
`(x + 2)^2 + (y + 10)^2 = 1.44`.

Explanation:

The standard form for a circle's equation has the following structure:

`(x - x_c)^2 + (y - y_c)^2 = r^2`

Where
`(x_c,y_c)` are the coordinates of the center of the circle and
`r` is the radius. Applying the data from the problem we have:

`(x - x_c)^2 + (y - y_c)^2 = r^2\\\[[x - (-2)]^2+ [y - (-10)]^2 = (1.2)^2\\(x + 2)^2 + (y + 10)^2 = 1.44`

Therefore the correct answer is the letter "C",
`(x + 2)^2 + (y + 10)^2 = 1.44`.