第3章矩阵、数组和符号运算 符号简化 > simple(cos(xr2-sin(x)2) simplif 2*cos(x)^2-1 raisin cos(x)2-sin(x) 2 combine(trig) COS(2 cos(x)-sin(x)*(cos(x)+sin(x)) expand cos(x)2-sin(x)2 combine符号简化 >> syms x >> simple(cos(x)^2-sin(x)^2) simplify: 2*cos(x)^2-1 radsimp: cos(x)^2-sin(x)^2 combine(trig): cos(2*x) factor: (cos(x)-sin(x))*(cos(x)+sin(x)) expand: cos(x)^2-sin(x)^2 combine: cos(2*x) 第3章 矩阵、数组和符号运算