Question

Patrick drew the incorrect graph shown below to represent the circle (x – 1)2 + (y + 3)2 = 4

Which statement explains why Patrick’s graph is incorrect?

Answers
A. The radius of the circle should be 2 instead of 4.

B. The center of the circle should be (1, 9) instead of (1, -3).

C. The center of the circle should be (-1, 3) instead of (1, -3).

D. The radius of the circle should be 16 instead of 4.

Answer 1

@PaxPolaris can you help me?

Answer 2

a circle with center \((h,k)\) and radius \(r\) will have the formula:
\[\Large \left( x-h \right)^2+\left( y-k \right)^2=r^2\]

Answer 3

Okay

Answer 4

so in your formula: what's the center supposed to be?

and what's the radius is supposed to be?

Answer 5

1, -3 r=4?

Answer 6

center is (1,-3)... yes

but \(\large r \ne 4\)

\[\Large \color{green}{r^2=4}\]

Answer 7

So r = 2?

Answer 8

Or 16?

Answer 9

2... you got it.

Answer 10

Great, thanks a million!