已知sin acos b=1,则cos(a+b)=急

已知sin acos b=1,则cos(a+b)=急 证明等式恒成立 sin^a+sin^b-sin^asin^b+cos^acos^b=1sin^a+sin^b-sin^asin^b+cos^acos^b=1 只需证sin^a(1-sin^b)+sin^b+cos^acos^b=1 只需证sin^acos^b+cos^acos^b+sin^b=1 这里到这里没有看懂 sin acos b=1/2,则cos asin b的取值范围 已知sin acos b=1,则sin(a-b)= 已知:sin^2A/sin^2B+cos^2Acos^2C=1,求证:tan^2Acot^2B=sin^2C 已知(sin A)^2+(sin B)^2+（sin C)^2=1,且A,B,C均为锐角,求cos Acos Bcos C的最大值 已知sin a+cos a= -1/5 求1）sin acos a 2）sin a-cos a 在△ABC中,若sin Acos B=1-cos Asin B,则此三角形一定是_____三角形. 求证sin²A+sin²B-sin²Asin²B+cos²Acos²B=1 求证：sin^2A+sin^2B-sin^2Asin^2B+cos^2Acos^2B=1 求证sin²a+sin²b-sin²asin²b+cos²acos²b=1 已知tana=-1/3,计算：1/2sin acos a+cos²a 若sin A+cos A=1,则sin Acos A=? 已知cos2a=（1/4),求cos^4a+sin^4+sin^2acos^2a的值 已知sinα=asinβ bcosα=acosβα、β为锐角求证 cosα=根号下[(a²-1)/(b²-1)] 求证1+sin a+cos a+2sin acos a/1+sin a+cos a=sin a+cos a 求证：sin^2A+sin^2B-sin^2Asin^2B+cos^2Acos^2B=1题中的^2为平方. 已知A(a,a^2)、B(b,b^2)(a≠b)两点的坐标,满足a^2sinθ+acosθ=1,b^2sinθ+bcosθ=1a^2sinθ+acosθ-1=0,b^2sinθ+bcosθ-1=0a=(-cosθ+√(cos^2θ+4sinθ)/(2sinθ)b=(-cosθ-√(cos^2θ+4sinθ)/(2sinθ)a+b=-cotθ.ab=-/sinθ/设直线Y=KX+C,坐标(a