1,已知sinA+sinA^2=1那么cosA^2+ cosA^4+ cosA^6=?
问题描述:
1,已知sinA+sinA^2=1那么cosA^2+ cosA^4+ cosA^6=?
2,(1+tan1) (1+tan2) (1+tan3) (1+tan4)……(1+tan45)=?
3,设6sin3B-(cos2A)^2=6,求A,B是多少?
4,已知 0
答
1、sinA+sinA^2=1,=》sinA=(-1+√5)/2,(sinA=(-1-√5)/2舍去)sinA=1-sin²A=cos²AcosA^2+ cosA^4+ cosA^6=sinA+sin²A+sin³A=sinA+sinA(sinA+sin²A)=2sinA=-1+√52、1=tan(1°+44°)=(tan1...