sina+cosa=1/5,0

已知4sinacosa-5sina-5cosa-1=0求sina.sina.sina+cosa.cosa.cosa的值． 已知（2sinA+cosA)/(sinA-cosA)=-5 求1、(sinA+cosA)/(sinA-cosA) 2、3 已知sina+cosa=1/5,0 知sina+cosa=1/5,0 sina+cosa=1/5(0 已知sina+cosa=-1/5(0 设sinA+cosA=1/5,0 已知sina+cosa=1/5(0 sina+cosa=1/5,0 已知sina+cosa=-1/5,0 sina+cosa=-1/5,0 已知sina+cosa=1/5求sinacosa,sina-cosa