sina+cosa=1 ,求sin^4(a)+cos^4(a)+sin(360°-a)cos(360°-a)的值如题
来源：学生作业帮助网 编辑：六六作业网 时间：2024/05/13 03:38:50
sina+cosa=1,求sin^4(a)+cos^4(a)+sin(360°-a)cos(360°-a)的值如题sina+cosa=1,求sin^4(a)+cos^4(a)+sin(360°-a)c
sina+cosa=1 ,求sin^4(a)+cos^4(a)+sin(360°-a)cos(360°-a)的值如题
sina+cosa=1 ,求sin^4(a)+cos^4(a)+sin(360°-a)cos(360°-a)的值
如题
sina+cosa=1 ,求sin^4(a)+cos^4(a)+sin(360°-a)cos(360°-a)的值如题
sin^4(a)+cos^4(a)+sin(360°-a)cos(360°-a)
=sin^4(a)+cos^4(a)+sin(-a)cos(-a)
=sin^4(a)+cos^4(a)+sin(a)cos(a)
=[sin^2(a)+cos^2(a)]^2-2sin^2(a)cos^2(a)+sin(a)cos(a)
=1-2sin^2(a)cos^2(a)+sin(a)cos(a)
sina+cosa=1
两边平方得
sin^2(a)+cos^2(a)+2sin(a)cos(a)=1
则1+2sin(a)cos(a)=1
则sin(a)cos(a)=0
所以1-2sin^2(a)cos^2(a)+sin(a)cos(a)=1
即sin^4(a)+cos^4(a)+sin(360°-a)cos(360°-a)=1
tana=sina/cosa=1/4,sin^2+cos^2=1,求sina=?
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
sina=2cosa,求(1)3sina+2cosa(2)sin²a+sina×cosa+3
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
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
已知tan a =-1/3,求sina-2cosa/3sina+4cosa和sin^2a-3sin a cos a +2的值.
已知（sin²A+4）/(cosA+1)=2,求（cosA+3）*（sinA+1）的值
已知sina+cosa=1/2 求：sin^4a+cos^4a
已知sina+cosb=1/2,cosa+sinb=3/4,求sin(a+b)
已知sina+cosa=1/3,求sin^a+cos^4a
sina-cosa=(-1/5),求sinacosa;sin*a+cos*a.*表示4次方
已知2cos^2a+3cosasina-3sin^2a=1.求tana.求(1)tana；（2）2sina-3cosa/4sina-9cosa.
已知tan(π-a)=2,求值：（1）2sin+2cosa/7sina+cosa（2）sina*cosa（3）4cosa^2+3sina^2
1.化简3(sina+cosa)^4+6(sina-cosa)^2+4(sin^6a+cos^6a)2.求证:(1-cosa)/(sina)=(sina)/(1+cosa)3.已知：-tana+1/(cosa)=1/2,求sina4.已知：sina+cosa=1/3,求tana+cota13 3：3/5 4：-9/4 答案我知道了,
(1-tana)/(1+tana)=2求(1)sina+cosa/(sina+2cosa) (2)sina-cosa(3)sin^2a-3cos^2a+1