Question

What is the general form of the equation for the given circle?

Answer 1

do you know the equation for a circle centered at origin?

Answer 2

x2+y2+r2

Answer 3

or just the general form

Answer 4

Do you know the general form?

Answer 5

oh and that should be = r^2 not plus r^2

Answer 6

thats what i meant

Answer 7

(x-h)^2 + (y-k)^2 = r^2 is the general form

Answer 8

(h,k) is the origin

so you need to figure out what the origin is

Answer 9

Do you know what it is?

Answer 10

how do i find it?

Answer 11

do you know the equation of the vertical and horizontal lines?

Answer 12

4 & 7??

Answer 13

the form for the equation of a vertical line is x=c (c is a constant)
horizontal is is y=c

Answer 14

so the vertical line is x=4

Answer 15

and the horizontal line is y=4

Answer 16

so your origin is (4,4)

Answer 17

now you need to find the radius and plug into the equation for a circle

Answer 18

is the radius 5?

Answer 19

no. How did you get 5?

Answer 20

i dont understand how to get it

Answer 21

the radius is the distance from the origin to an endpoint on the circle

Answer 22

9

Answer 23

how did you get 9?

Answer 24

subtract the y coordinate of the origin from the y coordinate of the endpoint connected by the vertical line

Answer 25

4-4?

Answer 26

that would be subtracting the x coordinate from the y coordinate.

Answer 27

try drawing the circle on graph paper with origin (4,4) and it should become clear