发布网友 发布时间:2022-05-04 22:55
共1个回答
热心网友 时间:2022-06-26 20:30
首先,利用两次积化和差公式: sinXsin2Xsin3X =-(1/2)(cos3X-cosX)sin3X =-1/4(sin6X)+1/2(sin4X)+1/2sin(2X) 分别设u1,u2,u3为-1/4(sin6X),1/2(sin4X),1/2sin(2X) 则u1的n阶导数为-1/4(sin(6X+n(π/2))*6^(n).....这个是复合函数求导 同理u2的n阶导数为1/2(sin(4X+n(π/2))*4^(n) u3的n阶导数为1/2(sin(2X+n(π/2))*2^(n) 最后y的n阶导数=u1的n阶导数+u2的n阶导数+u3的n阶导数 =-1/4(sin(6X+n(π/2))*6^(n)+1/2(sin(4X+n(π/2))*4^(n)+1/2(sin(2X+n(π/2))*2^(n)