Question

Which circles have their centers at the second quadrant?

Answer 1

the "Standard Form" for the equation of a circle
(x-a)^2 + (y-b)^2 = r^2

to be in the second quadrant means that the x will be negative and y is positive
so the equation in general will be something like this (x+a)^2 + (y-b)^2 = r^2

Answer 2

so b is correct because the center is (-12,9)
and also d is correct (-3,2)

Answer 3

Thank you! :)

Answer 4

So if I needed to find these in the 4th quadrent, would a,c, and D be correct?

Answer 5

yess

Answer 6

no wait

Answer 7

here they asked which one of the circles lies completely in the forth quadrant so you have to check the radius

Answer 8

got it?

Answer 9

for example in C the center is (2,-7) but the radius is \[\sqrt{64}\]=8
means that if you tried to draw it part of it will be in the third quadrant

Answer 10

Why do I have to check the radius? Can I plug it into a calculator?

Answer 11

Is it just A and D?

Answer 12

yess

Answer 13

Ohh okay. Thanks.