微积分：lt-3

结束上页 下页解?
结束例 3? 求正弦函数与余弦函数的 n阶导数?
y?sin x?
)2 s in (co s xxy?
)2 2s i n ()22 s i n ()2 co s ( xxxy?
)2 3s i n ()2 2co s ( xxy?
)2 4s i n ()2 3co s ()4( xxy?
一般地?可得
)2 s i n ()( nxy n? 即 )2 s i n ()( s i n )( nxx n?
用类似方法? 可得 )2 co s ()( co s )( nxx n?
)2 s in (co s xxy?
)2 2s i ()22 s in ()2 co s ( xxxy? ) 2s i n ()22 s i n ()2 co s ( xxxy?
)2 3s i n ()2 2co s ( xxy?
)2 4s i n ()2 3co s ()4( xxy?
)2 s i n ()( nxy n? 即 )2 s i n ()( s i n )( nxx n?