Question

A circle is represented by the equation below:
(x + 2)2 + (y − 4)2 = 225

Which statement is true?

Answer 1

statements are?

Answer 2

The circle is centered at (−2, 4) and has a radius of 15.

The circle is centered at (2, −4) and has a diameter of 15.

The circle is centered at (2, −4) and has a radius of 15.

The circle is centered at (−2, 4) and has a diameter of 15.

Answer 3

@study100 @nikato

Answer 4

the general form is

\[(x - h)^2 + (y - k)^2 = r^2\]

(h, k) is the centre... and r is the radius

so match it to your equation... and the radius is

\[\sqrt{225} = r\]

Answer 5

i am confused how to olug in the numbers @campbell_st

Answer 6

sorry I meant center****

Answer 7

ok... so in the bracket with x, what is the number... in your question...?

Answer 8

center (h,k)

Answer 9

so you have

\[(x + 2^2).. and (x - h)^2\]

any thoughts on the value of h

Answer 10

2? @campbell_st

Answer 11

well its 2 = -h..... so whats the value of h...?

Answer 12

same thing with k

\[(y - 4)^2 ...and....((y - k)^2\]

find the value of k

Answer 13

well if

2 = -h then h = -2

can you try finding the k value...?

Answer 14

value of k is 4? @campbell_st

Answer 15

thats correct... so the centre is (h, k)

so what do you think the centre is..?

Answer 16

so your centre is (-2, 4)

and you need to find the radius r\[\sqrt{225} = r\]

and that will be all you need

Answer 17

I have no idea. @campbell_st

Answer 18

here is a scientific calculator that will help you find

\[\sqrt{225}\]

http://web2.0calc.com/

Answer 19

15 @campbell_st

Answer 20

thats correct... now match your findings to the answers...

centre (-2, 4) radius 15

Answer 21

Choice A :) Thank u @campbell_st

Answer 22

great effort...