化简(sin^4α*cot^2α)-1
问题描述：
化简(sin^4α*cot^2α)-1
答
(sin^4α*cot^2α)-1 =(sin^4α*cos^2α/sin^2α)-1
=(sin^2α*cos^2α)-1=(0.5*sin2α)^2-1= -7/8-1/8*cos4α