Question

graph each circle how do u do it???
(y+1)^2=36-(x-3)^2

Answer 1

Center is -1,3
radius is 6

Answer 2

but how did you d it

Answer 3

first try to make your equation into the similar format of x^2 + y^2 = r^2

Answer 4

i need to understand

Answer 5

thank you funinabox!!

Answer 6

the x and y coordinates are just the (x,y) values solved for 0, the radius is the positive square root

Answer 7

ok so is it x^2+y^2=36

Answer 8

http://www.wolframalpha.com/input/?i=%28y%2B1%29%5E2%3D36-%28x-3%29%5E2

Answer 9

General equation of circle with center a,b is
\[(x-a)^2+(y-b)^2=r^2\]
r is radius
compare all equation of circle to this

Answer 10

yes but it would be (x-1)^2 + (y+1)^2 = 36

Answer 11

rewrite the equation as (x-3)^2 + (y + 1)^2 = 6^2 so the centre is (3, -1) the radius is r = 6

so looking at points the circle passes through... (3, -7) and (3 , 5) as well as ( -3, -1) and (9.-1)

Answer 12

ok thank you allll

Answer 13

and then set x-1 and y+1 to 0 and solve them and you will have the (x,y) coordinates for the center. it's just the thought process for doing it, as soon as you have it down you'll look at the equation and be like "bam" picture it in my head

Answer 14

i have another queestion??

Answer 15

how would you graph x^2+y^2-4x-12y-9=0

Answer 16

Complete squares

Answer 17

but how?

Answer 18

cuts the y axis at \[y = -1 \pm 3\sqrt{3}\]

cuts x axis at \[x = 3 \pm \sqrt{?}\]