Question

The equation of a circle is (x + 5)2 + (y - 3)2 = 16. Which graph best represents the circle?

http://learn.flvs.net/webdav/assessment_images/educator_geometry_v14/pool_Geom_3641_0800_Subtest_02_11/image0084e677a37.jpg


http://learn.flvs.net/webdav/assessment_images/educator_geometry_v14/pool_Geom_3641_0800_Subtest_02_11/image0074e677a37.jpg


http://learn.flvs.net/webdav/assessment_images/educator_geometry_v14/pool_Geom_3641_0800_Subtest_02_11/image0064e677a37.jpg


http://learn.flvs.net/webdav/assessment_images/educator_geometry_v14/pool_Geom_3641_0800_Subtest_02_11/image0054e677

Answer 1

I know that x is equal to -5 and y is equal to 3 and the radius is 4... but none of these seem right to me...

Answer 2

the center of the circle is at -5,3

Answer 3

Oh. Duh! Thank you.

Answer 4

Check again!
Look at each graph. Find the diameter of the circle, which is the number of units across (and up-down). If the diameter is 8, then the radius is 4.
Now count 4 units to the right of the left extremity, and 4 units higher than the bottom of the circle, that's the centre. If the centre is located at -5 units to the left of the y-axis and 3 units above the x-axis, you've got the right graphic.