\fNext, let's find fry, the second order partial derivative of f with respect to x and then y: a2 f O (x - y) fry = e ( x- y)2/ (2 2 2 ) axdy ay V2123 Using the chain rule and the product rule, we get: c- y fry = - e (x-y)2/(222)_ (2 - y) a e (x-y)2/(222) ay V2723 V2723 dy 1 a fry = - e (2 - 4 ) 2 / ( 2 2 2 ) ( 2 - y ) e (x-y)2/(222) V 2123 V27123 ay