Find the second partial derivative fxxf_{xx}fxx for f(x,y)=sin(xy)f(x, y) = \sin(xy)f(x,y)=sin(xy).
−y2sin(xy)-y^2 \sin(xy)−y2sin(xy)
−x2sin(xy)-x^2 \sin(xy)−x2sin(xy)
cos(xy)\cos(xy)cos(xy)
−xy2sin(xy)-xy^2 \sin(xy)−xy2sin(xy)