Question

A circle is graft with the center on the origin. The area of the circle is 144 square units. What are the X intercepts of the graph?

round to the nearest 10th

Answer 1

(x-h)^2+(y-k)^2=r^2
center is (h,k)
radius is r

given
center is (0,0
find radius

area=pir^2
144=pir^2
divide both sides by pi
144/pi=r^2
sqrt both sides
12/√pi=r
sub for r in the equation

(x-0)^2+(y-0)^2=(12/√pi)^2
x^2+y^2=(12/√pi)^2

the radius is 12/√pi, or (12√pi)/pi
that is the distance from 0 to any point on the circle

xints are (-12√pi)/pi and (12√pi)/pi
aprox
-6.77 and 6.77
round
-6.8 and 6.8

the x intercepts are x=-6.8 and 6.8 or the points (-6.8,0) and (6.8,0)