(2) lim (kA(x))=kA x→>x (3) lim (A(x)B(x))=AB x->x0 定义:如果A(x)=(an(x)mxn的所有各元素 .(x)(L n)在点x 处(或在区间[a,b]上)可导,便称此函数矩阵 A(x)在点x=x0处或在区间[a,b]上) 并且记为
0 0 (2) lim ( ( )) (3) lim ( ( ) ( )) x x x x kA x kA A x B x AB → → = = 定义:如果 的所有各元素 在点 处(或在区间 上)可导,便称此函数矩阵 在点 处(或在区间 上)可导, 并且记为 ( ) ( ( )) A x a x = ij m n ( )( 1, , ; 1, , ) a x i m j n ij = = 0 x x = [ , ] a b A x( ) 0 x x = [ , ] a b
A(x0) in4(x+△x)-4(x) da(x Ax→>0 △x 11(0 12(0 2(x0) a21(x0)a2(x0) 2n(~0 am (ro)a m2( mn
0 0 0 0 0 11 0 12 0 1 0 21 0 22 0 2 0 1 0 2 0 0 d ( ) ( ) ( ) ( ) lim d ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) x x x n n m m mn A x A x x A x A x x x a x a x a x a x a x a x a x a x a x → = + − = = =
函数矩阵的导数运算有下列性质: (1)A(x)是常数矩阵的充分必要条件是 d4(x) 0 dx (2)A(x=(a, (xmm, B(x)=(6, (x)) 均可导,则 [A(x)+B(x)]= da(x) dB(x)
函数矩阵的导数运算有下列性质: (1) 是常数矩阵的充分必要条件是 (2) 设 均可导,则 A x( ) d ( ) 0 d A x x = ( ) ( ( )) , ( ) ( ( )) A x a x B x b x = = ij m n ij m n d d ( ) d ( ) [ ( ) ( )] d d d A x B x A x B x x x x + = +
(3)设k(x)是x的纯量函数,A(x)是函数矩 阵,(x)与A(x)均可导,则 d (k(r)A(x)7=dk(A(x)+k(r dA(x) d 特别地,当k(x)是常数k时有 dr a()]=k da()
d d ( ) d ( ) [ ( ) ( )] ( ) ( ) d d d k x A x k x A x A x k x x x x = + (3)设 是 的纯量函数, 是函数矩 阵, 与 均可导,则 特别地,当 是常数 时有 k x( ) x A x( ) k x( ) A x( ) k x( ) k d d ( ) [ ( )] d d A x kA x k x x =
(4)设A(x),B(x)均可导,且A(x)与B(x)是 可乘的,则 [A(xB(x) d4(x) B(x)+a(x) db(x) xX 因为矩阵没有交换律,所以 (x)≠24(x) d4(x) A(x)≠3A2(x) d4(x) X
(4) 设 均可导,且 与 是 可乘的,则 因为矩阵没有交换律,所以 A x B x ( ), ( ) A x( ) B x( ) d d ( ) d ( ) [ ( ) ( )] ( ) ( ) d d d A x B x A x B x B x A x x x x = + 2 3 2 d d ( ) ( ) 2 ( ) d d d d ( ) ( ) 3 ( ) d d A x A x A x x x A x A x A x x x