2cos(AB)/2*sin(A-B)/2*2sin(AB)/2*cos(A-B)/2=sinBsi

1-cos^2(A)cos^2(B)+sin^2(A)sin^2(B)求化简AB是数1-cos^2(A)cos^2(B)+sin^2(A)sin^2(B)求化简AB是数1-cos^2(A)cos^2(

化简cos(a+b)cos(a-b)+sin^2b化简cos(a+b)cos(a-b)+sin^2b化简cos(a+b)cos(a-b)+sin^2bcos(a+b)cos(a-b)+sin^2b=(

a=sinpai/6b=cospai/6a^2-ab-b^2=?a=sinpai/6b=cospai/6a^2-ab-b^2=?a=sinpai/6b=cospai/6a^2-ab-b^2=?a=si

化简sin^2a+sin^2b-sin^2a*sin^2b+cos^2a*cos^2b化简sin^2a+sin^2b-sin^2a*sin^2b+cos^2a*cos^2b化简sin^2a+sin^2

sin^2a+sin^2b-sin^2a*sin^2b+cos^2a*cos^2b化简sin^2a+sin^2b-sin^2a*sin^2b+cos^2a*cos^2b化简sin^2a+sin^2b-

sin^2(A)+sin^2(B)-sin^2(A)sin^2(B)+cos^2(A)cos^2(B)sin^2(A)+sin^2(B)-sin^2(A)sin^2(B)+cos^2(A)cos^2(

证明sin^2A+sin^2B-sin^2A*sin^2B+cos^2A*cos^2证明sin^2A+sin^2B-sin^2A*sin^2B+cos^2A*cos^2B=1证明sin^2A+sin^

cos^2a-cos^2b=m,那么sin(a+b)sin(a-b)=?cos^2a-cos^2b=m,那么sin(a+b)sin(a-b)=?cos^2a-cos^2b=m,那么sin(a+b)si

证明sin(A+B)sin(A-B)=cos^2B-cos^2A证明sin(A+B)sin(A-B)=cos^2B-cos^2A证明sin(A+B)sin(A-B)=cos^2B-cos^2Asin(

求证cos(a+b)cos(a－b)=cos^2b－sin^2a求证cos(a+b)cos(a－b)=cos^2b－sin^2a求证cos(a+b)cos(a－b)=cos^2b－sin^2acos(

求证cos(a+b)cos(a-b)=cos^2a-sin^2b求证cos(a+b)cos(a-b)=cos^2a-sin^2b求证cos(a+b)cos(a-b)=cos^2a-sin^2b原式=c

若A,B两点坐标为A（cosα,sinα,1),B(2cosθ,2sinθ,1）,则|AB|的取值范围若A,B两点坐标为A（cosα,sinα,1),B(2cosθ,2sinθ,1）,则|AB|的取值

sin(a-b)*cosa-cos(a-b)*sina=1/5,则cos2b的值是sin(a-b)*cosa-cos(a-b)*sina=1/5,则cos2b的值是sin(a-b)*cosa-cos(

(sinα-sinβ)/sin(α-β)=a,(cosα-cosβ)/sin(α+β)=b,求sin(α-β)的值答案是-ab/(1+a^2b^2)(sinα-sinβ)/sin(α-β)=a,(co

由cos(a+b)=cosacosb-sinasinbcos(a-b)=cosacosb+sinasinb解题设a为锐角,证：1、2分之根3乘cosa+2分之1乘sina=cos(6分之π-a)2、c

化简（sin(a-b)-2sinacosb）/2sinasinb+coa(a+b)化简（sin(a-b)-2sinacosb）/2sinasinb+coa(a+b)化简（sin(a-b)-2sinac

化简sin^2acos^b-cos^2asin^2b+cos^a-cos^2b化简sin^2acos^b-cos^2asin^2b+cos^a-cos^2b化简sin^2acos^b-cos^2asi

已知向量a=(cosα,sinα),b=(sinβ,cosβ),β属于(0,π),tanβ/2=1/2,向量ab=5/13．求sinβ,cosβ,sinα求详解已知向量a=(cosα,sinα),b=

Cos(a+b)*cos(a-b)=1/5求cos^2-sin^2Cos(a+b)*cos(a-b)=1/5求cos^2-sin^2Cos(a+b)*cos(a-b)=1/5求cos^2-sin^2原

cos(A+B)cos(A-B)化简的结果是（）A.cos^2A-sin^2BB.sin^2A-sin^2BC.cos^2A-cos^2BD.sin^2A-COS^2B怎么作的?cos(A+B)cos