求1-sin^6α-cos^6α\1-sin^4α-cos^4α的值解题过程,

问题描述:

求1-sin^6α-cos^6α\1-sin^4α-cos^4α的值解题过程,

首先我们知道1=(sin^2(α)+cos^2(α))^3同时1=(sin^2(α)+cos^2(α))^2,不妨设a=sin^2(α),b=cos^2(α)展开后可得(3ab(a+b))/(2ab)=3/2(a+b)=3/2