posted by 3.1415926... on .
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!!!!!!
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
That is not right.
So, if it's not right, maybe you could let us know where we went wrong. The idea is to help here, you know.
the answer is 4pi-8 . FOR SURE!!
it is 4pi-8