Question

Write the standard equation of the circle below.
http://curriculum.kcdistancelearning.com/courses/GEOMx-HS-A09/b/assessments/C-EquationsofaCircleQuiz/Geometry_7.3_Quiz_FINAL_22q.jpg @whpalmer4

Answer 1

okay, this is just working backwards compared to what we did in the previous problem. what are the coordinates of the center of this circle?

Answer 2

(-1, 2)

Answer 3

good. so what are the values of \(h,k\) that we'll plug into the formula?

Answer 4

(-1, 2) or are those x and y?

Answer 5

yes, h= -1, k = 2

now what is the radius we are going to use?

Answer 6

i am not so sure...can you give me a hint?

Answer 7

how far is it from the center to the edge of the circle?

Answer 8

1 unit/square?

Answer 9

looks that way to me!

Answer 10

ok so the radius would be 1 unit?

Answer 11

yes

Answer 12

so plug in \[r=1, h=-1,k = 2\] in that formula, and what comes out?

Answer 13

@whpalmer4 sorry i had to eat lunch! can you still help?

Answer 14

@whpalmer4

Answer 15

yes, I'm still waiting for you to answer my last question :-)

Answer 16

ok i got
(x - 1)2 + (y + 2)2 = 1 @whpalmer4

Answer 17

(x-1)^2+(y+2)^2=1 @whpalmer4

Answer 18

@surjithayer oh can you help? :) please?

Answer 19

formula is (x-h)^2+(y-k)^2=r^2
you have not plugged correctly the values of h and k
see the signs + or -

Answer 20

yeah, we really need to work on getting you to match things up exactly, not just approximately.

if the formula says \((x-h)\) and you have \(h = -1\), then you do\[(x- (-1)) = (x+1)\]

Answer 21

@whpalmer4 ok so the answer would actually be (x + 1)2 + (y - 2)2 = 1

Answer 22

yes, although you should write that with ^ to indicate exponents:

(x+1)^2 + (y-2)^2 = 1

(and remember that it was really 1^2 which just happens to equal 1)

Answer 23

ah ok thanks!