sin374°cos148°+sin77°cos58° 和sin(a+b)cos(γ-b)-cos(b+a)sin(b-
sin374°cos148°+sin77°cos58° 和sin(a+b)cos(γ-b)-cos(b+a)sin(b-
tan525° 化简 用和(差)角公式 sin347°cos148°+sin77°cos58°化简 sin164°sin
用和差角公式化简,化简sin58'cos37'-cos58'sin37'和sin(a b)cosb cos(a-b)si
sin(a-b)sin(b-r)-cos(a-b)cos(r-b)
貌似不难,sin(a+b)cos(c-b)-cos(b+a)sin(b-c)sin(a-b)sin(b-c)-cos(a
cos(a-b)cosb-sin(a-b)sinb
已知B是第三象限的角,cos(a+B)×cosa+sin(a+B)×sina=-4/5,求cos(90°+B)的值.
求直线斜率已知点A(cos 80°,sin 80°),B (cos 20°,sin 20°),则过 A ,B 两点的直线
化简 cos(a+b)cosa+sin(a+b)sina=_______ cos(31°-a)cos(29°+a)-co
为什么sin(a+b)-sina=2sin(b/2)cos(a+b/2)
和差倍半公式怎么证明怎么用单位圆证明sin(a ± b)=sin a x cos b ± cos a sin bcos(
向量a等于(cos阿尔法,sin阿尔法)向量b等于(cos贝塔,sin贝塔)