Patrick B. answered 02/19/19
Math and computer tutor/teacher
y^2 ( 2yy') + (y^2 - 4)2yy' = x^2( 2x) + (x^2-5)(2x)
(2yy')( 2y^2 - 4) = (2x) ( 2x^2 - 5)
(2yy')(y^2-2) = x(2x^2 - 5) <--- divides everything by 2
y' = x(2x^2 - 5)/((2y)(y^2-2))
the slope is m= 0 at x=0
y = -2