QUESTION $2$

If $f(x,y)=cos(x^{2}y),$ the $f_x(x,y)-f_y(x,y)=$

a$.2$xycos$(x^{2}y)$

b$.x^{2}sin(x^{2}y)$

c$.(x^2-2xy)sin(x^{2}y)$

d$.(x^2+2xy)sin(xy)$

e$.x^{2}cos(x^{2}y)$