Ex 11 3 4 X2 25 Y2 100 1 Find Foci Latus Rectum Ex 11 3 As someone else stated, x 2 y 2 = 25 is a relationship describing a circle this link shows the generic equation and the meanings as such In this case, the center of the circle is at the point (0,0) and the radius is 25 units 1 Share Report Save level 1 6ySOLUTION 1 Begin with x 3 y 3 = 4 Differentiate both sides of the equation, getting D ( x 3 y 3) = D ( 4 ) , D ( x 3) D ( y 3) = D ( 4 ) , (Remember to use the chain rule on D ( y 3) ) 3x 2 3y 2 y' = 0 , so that (Now solve for y' ) 3y 2 y' = 3x 2, and Click HERE to return to the list of problems SOLUTION 2 Begin with (xy) 2 = x y 1 Differentiate both sides X 2 y 2 25 x 2y 10