Question

Find an equation of the circle shown below.

Answer 1

A. (x + 10)2 + (y − 10)2 = 289

B. (x − 10)2 + (y − 10)2 = 289

C. (x − 10)2 + (y + 10)2 = 289

D. (x − 10)2 + (y − 10)2 = 17

Answer 2

find the center using the midpoint formula

once you have the center, use the distance formula to find the radius

Answer 3

what is the mid point formula?

Answer 4

if you have two points (x1,y1) and (x2,y2)

the midpoint, call it the point (p,q) is defined by

p = (x1 + x2)/2

q = (y1+y2)/2

Answer 5

ok

Answer 6

so the answer is (B)?

Answer 7

what did you get for the center

Answer 8

for the midpoint Ii got 10 and 10
for the distance I got 349

Answer 9

midpoint is (10,10)

but the distance from center to either endpoint is not 349

Answer 10

then how to find it?

Answer 11

are you using the distance formula

d = sqrt( (x2 - x1)^2 + (y2 - y1)^2 )

??

Answer 12

I used this one
http://www.google.com/search?gs_rn=17&gs_ri=psy-ab&cp=10&gs_id=12&xhr=t&q=distance+formula&bav=on.2,or.r_qf.&bvm=bv.49147516,d.cGE&biw=1440&bih=795&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=M_feUff3D-HsigLgkYDQDQ&surl=1&safe=active#facrc=_&imgdii=_&imgrc=lCL5kVe5vsaFzM%3A%3Bpqop7_Eu8omN4M%3Bhttp%253A%252F%252Fcs.selu.edu%252F~rbyrd%252Fmath%252Fdistance%252Fdist_ex1.gif%3Bhttp%253A%252F%252Fcs.selu.edu%252F~rbyrd%252Fmath%252Fdistance%252F%3B439%3B171

Answer 13

ok that's the same formula

Answer 14

yeah I got 349

Answer 15

so what did you get when you plugged the values in

Answer 16

before you got 349

Answer 17

ie what was any of your intermediate steps

Answer 18

I did like
(18--5)2+(25-2)2

Answer 19

i see, thanks

Answer 20

18 and -5 are mixed up because 18 is the x coordinate of the second point while -5 is the y coordinate of the first point

Answer 21

you should be subtracting the x coordinates together

then the y coordinates together

Answer 22

i did

Answer 23

no you should be doing this

(18 - 2)^2 + (-5 - (-25))^2

Answer 24

x1=2,x2=18
y1=.5 and y2=25

Answer 25

see the difference?

Answer 26

yeah

Answer 27

which is 34 right

Answer 28

oh sry, i mixed them up myself

Answer 29

its ok

Answer 30

it should be this

(18 - 2)^2 + (25 - (-5))^2 = 1156

then you take the square root of that to get 34

so you got it right

Answer 31

now you cut this in half to get 17, this is the radius

so r = 17 ----> r^2 = 289

Answer 32

So i got the answer RIGHT (B)

Answer 33

correct

Answer 34

thanks

Answer 35

np