Question

Four circles of unit radius are drawn with centers (1,0), (-1,0), (0,1), and (0,-1). A circle with radius 2 is drawn with the origin as its center. What is the area of all points which are contained in an odd number of these 5 circles? (Express your answer in the form "a pi + b" or "a pi - b", where a and b are integers.)


Can you tell what the answer is? I want a clear explanation too. Thanks!!!!!!

Answer 1

the small circles intersect in lens-shaped areas of pi/2 - 1

each small circle has area pi

The large circle has area 4pi

The points in the lenses and the large circle outside the small circles lie in 1 or 3 circles.

4pi - 4(pi) + 4(pi/2-1) = 2pi-4

Answer 2

That is not right.

Answer 3

So, if it's not right, maybe you could let us know where we went wrong. The idea is to help here, you know.

Answer 4

the answer is 4pi-8 . FOR SURE!!

Answer 5

it is 4pi-8

Answer 6

correct ^^^^^