单选题 难度 3 设 z=f(x2−y2,2x+3y)z=f(x^2-y^2,2x+3y)z=f(x2−y2,2x+3y)，则 ∂z∂x=\dfrac{\partial z}{\partial x}=∂x∂z=（ ） A 选项 A 2xf1′+3f2′2x f_1'+3f_2'2xf1′+3f2′ B 选项 B 2xf1′−2yf2′2x f_1'-2y f_2'2xf1′−2yf2′ C 选项 C 2xf1′+2f2′2x f_1'+2f_2'2xf1′+2f2′ D 选项 D 2xf1′−3f2′2x f_1'-3f_2'2xf1′−3f2′ 答案与解析 微信扫描二维码 免费获取正确答案和解析
