Question

Find the coordinates of the points of intersection of the circle with the y-axis. (x +5 )^2 + (y-4)^2 =169

Answer 1

Let x = 0 if you want to find the y intercepts.

Answer 2

how do you know what x equals?

Answer 3

Replace x with 0 because if the point is on the y axis, its x coordinate is 0.

Answer 4

\[(0+5)^2+(y-4)^2=169\]

Answer 5

if it was asking for x axis, would it be 0 too?

Answer 6

I got (0,16)

Answer 7

\[25+(y-4)^2=169\]
\[(y-4)^2=144\]
\[y-4=12 or y-4=-12\]
\[y=16 or y = -8\]

Answer 8

I don't know what you mean "asking for the x axis" What does that mean?

Answer 9

I mean like.. if a question like this one is asking for the x axis.. would it equal 0 like the y axis does?

Answer 10

If you wanted to find the x intercepts you would replace y with 0.

Answer 11

ok so my answer would be (0,16) correct?

Answer 12

wait it says coordinates..

Answer 13

Because every point on the x axis has a y coordinate of 0

Answer 14

Did you not see my work?

Answer 15

ohh no I'll check it out

Answer 16

This circle crosses the y axis in TWO places.

Answer 17

oh

Answer 18

So (0,16) and (0,-8)

Answer 19

But wouldnt we just change 16 to negative?

Answer 20

how did you end up with -12

Answer 21

in your steps