admin百科知識 2022-02-13 19:10:28 若sin(π6-啊)=13,則cos(2π3+2a)=?若sin(π/6-啊)=1/3,則cos(2π/3 2a)=?網友廻答:匿名網友sin(π/6-a)=1/3sin(π/6-a)=cos[π/2-(π/6-a)]=cos(π/3 a)=1/3cos(2π/3 2a)=cos[2(π/3 a)]=2[cos(π/3 a)]^2-1=-7/9 db標簽 生活常識_百科知識_各類知識大全»若sin(π6-啊)=13,則cos(2π3+2a)=?
0條評論