What is the partial derivative fxyf_{xy}fxy of f(x,y)=excosyf(x, y) = e^x \cos yf(x,y)=excosy?
−exsiny-e^x \sin y−exsiny
exsinye^x \sin yexsiny
excosye^x \cos yexcosy
−excosy-e^x \cos y−excosy