Question

A circle has its center at (-1, 2) and a radius of 3 units. What is the equation of the circle?

Answer 1

Select one:
a. (x - 1)2 + (y + 2)2 = 3
b. (x + 1)2 + (y - 2)2 = 3
c. (x + 1)2 + (y + 2)2 = 9
d. (x + 1)2 + (y - 2)2 = 9

Answer 2

@kc_kennylau

Answer 3

The equation for a circle with center (a,b) and radius r is:
(x-a)^2+(y-b)^2=r^2

Answer 4

Plug in the values

Answer 5

i think i know it has to be between c and d though

Answer 6

Seriously, why does everyone here say the answer is between blah blah blah and blah blah blah

Answer 7

There is always only one answer, and all the other ones are wrong...

Answer 8

because i said it CAN BE BETWEEN B AND C

Answer 9

go on go on

Answer 10

hint:

i'll give you a demo

a circle has center (-3, 4) and radius 2

equation of circle is
(x−h)2+(y−k)2=r2

where (h,k) is the center and r is the radius

since in my example h is -3 and k is 4 i will have
(x−−3)2+(y−4)2=22

⟹(x+3)2+(y−4)2=4

do you get the idea?