The elliptic equation is x 2/100+y 2/64 =1.

So c=6

F2(-6，0)

K=(Y-0)/(X+6)= minus 4 times of the radical sign and 3.

While p is on an ellipse, you can get the value of y by bringing the coordinates of point P into the elliptic equation.

S= 1/2 times 2c times y.