已知x属于实数,n属于整数,且f（sinx）=si - 知识问答

已知x属于实数,n属于整数,且f（sinx）=sin(4n+1)x,求f(cosx).

1个回答

因为 f(sin x)=sin [ (4n+1) x ] ,
所以 f(cos x)=f[ sin (x +pi/2) ]
=sin [ (4n+1) (x +pi/2) ]
=sin [ (4n+1) x +2n *pi +pi/2]
=sin [ (4n+1) x +pi/2 ]
=cos [ (4n+1) x ].

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