Question

A circle has its center at (−2, −3) and a radius of 3 units. What is the equation of the circle?

(x + 2)2 + (y − 3)2 = 9
(x − 2)2 + (y − 3)2 = 3
(x + 2)2 + (y + 3)2 = 9
(x + 2)2 + (y + 3)2 = 3

Answer 1

so the formula will be (x-x1) + (y-y1) = r^2

Answer 2

general form is
(x - a)^2 + (y - b)^2 = r^2

where (a,b////0 is the centre and r = radius

Answer 3

so first of all, the -2 would be your x1

Answer 4

* (a,b) is the centre

Answer 5

making the first part (x+2)

Answer 6

so what would you think the second part would be?

Answer 7

oh i screwed up, the (x+2) would be squared too

Answer 8

( y - (-3))^2 = ?

Answer 9

what does a double negative give you?

Answer 10

and you have a radius of 3, so the number on the right side would be three squared

Answer 11

so what does that make?

Answer 12

A

Answer 13

close

Answer 14

remember that your y coordinate is at -3

Answer 15

and the formula suggests subtracting your y coordinate

Answer 16

so you're subtracting a negative

Answer 17

so c

Answer 18

yep!

Answer 19

thank you

Answer 20

np