An ellipse with equation x2a2+y2b2=1 contains the circles (x−1)2+y2=1 and (x+1)2+y2=1. Then the smallest possible area of the ellipse can be expressed in the form kπ. Find k.
The center of the ellipse will be the origin
The length of the major axis is 4....so a is 1/2 of this = 2
The length of the minor axis = 2sqrt(2)....so.....b is 1/2 of this = sqrt(2)
So....the equation of the ellipse is
x^2 y^2
___ + _________ = 1
2^2 [sqrt(2)]^2
x^2 y^2
___ + _____ = 1
4 2
The area of the ellipse = pi * a * b = pi * 2 * sqrt(2) = 2sqrt(2) pi
So
k = 2sqrt (2)
Here is the graph : https://www.desmos.com/calculator/ovso9le6pj