f(x,y)=xy+e^x x arctanx/y ,求f(x+y,x-y)
问题描述：
f(x,y)=xy+e^x x arctanx/y ,求f(x+y,x-y)
答
原式=x²-y²+e^(x+y)arctan(x+y)/(x-y)
f(x,y)=xy+e^x x arctanx/y ,求f(x+y,x-y)
原式=x²-y²+e^(x+y)arctan(x+y)/(x-y)