admin百科知識 2022-02-12 23:03:21 sin(a+b)=-35,sin(b-派4)=1213,ab屬於(3派4,派)求cos(a+派4)sin(a b)=-3/5,sin(b-派/4)=12/13,ab屬於(3派/4,派)求cos(a 派/4)網友廻答:匿名網友cos(a pi/4) = cos(a b-b pi/4) = cos(a b)cos(b-pi/4) sin(a b)sin(b-pi/4) = -4/5*5/13-3/5*12/13 =-56/65 db標簽 生活常識_百科知識_各類知識大全»sin(a+b)=-35,sin(b-派4)=1213,ab屬於(3派4,派)求cos(a+派4)
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