The radius of the circle passing through the foci of the ellipse x^2 4 + 4 y^2 7 =1 and having its centre at ( 1 2 , 2 ) is

Step-by-step solution

Given equation of ellipse is x^2 4 + y^2 7 4 =1 Here, a^2=4 and b^2= 7 4 ^2=a^2 (1-e^2 ) 7 4 =4 (1-e^2 ) e^2=1- 7 16 = 9 16 e= 3 4 , Thus, the foci are ( 3 2 , 0 ) . The radius of the required circle aligned & = ( 3 2 - 1 2 )^2+(0-2)^2 & = 5 aligned