Question

Help!
Find the center and the radius of the circle.

x2 + (y + 3)2 = 25

A) C(0, -3); r = 25
B) C(0, 3); r = 5
C) C(3, 0); r = 5
D) C(0, -3); r = 5

Answer 1

i know first you factor

Answer 2

\[(x-h)^2+(y-k)^2=r^2\]is a circle radius r with center at (h,k) identify h and k and r, then you have your answer

Answer 3

no factoring necessary ;)

Answer 4

huh really because you have a 2(y+3) dont you need to distrubute that first

Answer 5

\[x^2+(y+3)^2=25\]

Answer 6

lol, yes it would seem that way, but I know they mean
\[x^2 + (y + 3)^2 = 25\]
otherwise it would not be a circle.
people get lazy and just copy and paste questions, so it looks like a coefficient.

Answer 7

it B right?!

Answer 8

oh its an exponent

Answer 9

shoot

Answer 10

its D

Answer 11

why is it D -3? i thought it would be B isn't the 3 positive?

Answer 12

careful about the minus sign!\[x^2+(y+3)^2=25=x^2+(y-(-3))^2=25\]so k=-3

Answer 13

look at what turingtest wrote at the begining
25 = r^2
so r=5
and the general form of the circle is\[(x-h)^2+(y-k)^2=r^2\]
the center is (h,k)

Answer 14

AWWW okay i see i see!

Answer 15

thank u!!