Find the area of the region bounded by the latus recta of the ellipse `x^2/a^2+y^2/b^2=1` and the targets to the ellipse drawn at their ends

Explanation

equation of tangent PR

`(xx_1)/a^2+(yy_1)/b^2=1`

putting the extreme values

`(xe)/a+y/a`=1 -(1)

equation of tangent QR

`(xe)/a-y/b=1` -(2)

adding 1 and 2

`(2xe)/a=2`

...