Question

If the point (1, 5) lies on a circle whose center is at the origin, what is the equation of the circle?

A.) x(squared) + y(squared) = 26

B.) x(squared) + y(squared) = 16

C.) x(squared) + y(squared) = 13

D.) x(squared) + y(squared) = 11

Answer 1

@peachpi

Answer 2

the anwer is C I THINK

Answer 3

The radius is the distance from the center to the circle, so use the distance formula again to find the radius.
r = distance between (0,0) and (1,5)

Answer 4

the equation for a circle actually comes directly from the distance formula

Answer 5

I got b, is that right?

Answer 6

NO ITS c

Answer 7

no.

Answer 8

hmmm...

\[x^2 + y^2 = r^2\]
(x,y) = (1,5)
\[1^2 + 5^2 = 1+25=26\]

Answer 9

ITS CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC