第3章矩阵、数组和符号运算 c.符号微分和差分 微分和差分 >>syms x t, Diff(s) Diff(s,v A=cos(x t), sin(x t); -sin(x*t), cos(x t)I A Diff(s, n) s(x*t), sin(x t) Diff(S, v, n) [-sin(x*t), cos(x t) > syms x >diff(a, x) %> diff(a, 'x') ans diff(sin(x 2) [-sin(x*t)*t, cos(x*t)*t] ans [-cos(x*t)*t,-sin(x*t) *t 2 cos(x2)*x > diff(a, t, 2 s>diff(t, 6) ans [-cos(x*t)*x2, -sin(x*t)*x2 720 sin(x*t)*2,-coS(x*t)*x/2c. 符号微分和差分 ➢微分和差分 Diff(S) Diff(S,v) Diff(S,n) Diff(S,v,n) >> syms x >> diff(sin(x^2)) ans = 2*cos(x^2)*x >> diff(t^6,6) ans = 720 第3章 矩阵、数组和符号运算 >> syms x t; >> A=[cos(x*t),sin(x*t);-sin(x*t),cos(x*t)] A = [ cos(x*t), sin(x*t)] [ -sin(x*t), cos(x*t)] >> diff(A,x) %>> diff(A,'x') ans = [ -sin(x*t)*t, cos(x*t)*t] [ -cos(x*t)*t, -sin(x*t)*t] >> diff(A,t,2) ans = [ -cos(x*t)*x^2, -sin(x*t)*x^2] [ sin(x*t)*x^2, -cos(x*t)*x^2]