作业帮sina+sinβ=1,求cosa+cosβ的取值范围
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/17 04:25:08
sina+sinβ=1,求cosa+cosβ的取值范围
sina+sinβ=1,求cosa+cosβ的取值范围
sina+sinβ=1,求cosa+cosβ的取值范围
用b
sin²a+sin²b+2sinacosa=1²
令cosa+cosb=k
cos²a+cos²b+2cosacosb=k²
相加,sin²+cos²=1
所以2+2(cosacosb+sinasinb)=k²+1
cos(a-b)=(k²-1)/2
则-1<=(k²-1)/2<=1
-1<=k²<=3
即0<=k²<=3
所以-√3<=cosa+cosb<=√3
sina=2cosa,求(1)3sina+2cosa(2)sin²a+sina×cosa+3
sina+sina=1 求cosa+cosa
sina+cosa/sina-cosa=2 求sin^2a-2sinacosa+1
tanθ=(sina-cosa)/(sina+cosa) 求sina-cosa/sinθ
sina+sinβ=1,求cosa+cosβ的取值范围
tana=sina/cosa=1/4,sin^2+cos^2=1,求sina=?
(1-tana)/(1+tana)=2求(1)sina+cosa/(sina+2cosa) (2)sina-cosa(3)sin^2a-3cos^2a+1
1:已知sina+cosa=根2求sina cosa sin(4方)a+cos(4方)的值2:已知:sina+cosa=1/5(0
已知tana/tana-1=-1,求下列各式的值（1）sina-3cosa/sina+cosa(2)sin^2a+sina*cosa+2
已知tana/（tana-1）=-1,求下列各式的值（1）sina-3cosa/sina+cosa(2)sin^2a+sina*cosa+2
sin(a+kπ)=2cos[a+(k+1)π].求5cosa+3sina/4sina-2cosa
sin(a+kπ)=2cos[a+(k+1)π].求5cosa+3sina/4sina-2cosa
已知sinA=1/5,求2sin(A+B)cosA-sin(2A+B)
已知sina+cosa=1/5求sinacosa,sina-cosa
sina+cosa=1/5,求sina.cosa
3sina-cosa/sina+3cosa=1,求tana
tana=-1/2,求2cosa-sina/sina+cosa
已知2sina=cosa+1,求sina+cosa