matlab中,一个函数有多个自变量,怎么分别求导并代入具体数值,举个例子...答:syms x1 x2 x3 f = x1^2+x2^2+x3^2;fx1 = diff(f,x1);fx2 = diff(f,x2);fx3 = diff(f,x3);x11 = input('请输入整数x1:');x22 = input('请输入整数x2:');x33 = input('请输入整数x3:');subs(fx1,x1,x11)subs(fx2,x2,x22)subs(fx3,x3,x33)输出的subs就是赋值...