Question

Which of the following is the equation of a circle with center (-4, 1) and radius of 8?

(x - 4)2 + (y + 1)2 = 64

(x + 4)2 + (y - 1)2 = 64

(x - 4)2 + (y + 1)2 = 8

(x + 4)2 + (y - 1)2 = 8

Answer 1

the second one

Answer 2

the second one

Answer 3

equation of a circle is (x-a)^2 + (y-b)^2 = r^
where r is the radius and its center is (a,b)

Answer 4

r^2*

Answer 5

do u guys know the formula for circumference? i cant believe i do not remember this stuff lol

Answer 6

i believe its 2piR

Answer 7

and area is pir^2?

Answer 8

yea its 2pi(r) where r is the radius
pi(r)^2 is the area of a circle

Answer 9

you can think of area is larger than the circumerfernce since circumerference only measures a line, and r^2 is larger than 2r

or if you know derivatives, the circumference is the derivative of the area