2cos平方米a/2+cosa=0
化简(1+sina+cosa)[sin(a/2)-cos(a/2)]/根号(2+2cosa) (0°
2cos²A-3cosA+1=0 (cosA-1)(2cosA-1)=0 这两步的变化不懂
证明(1-cos^2a)/(sina+cosa)-(sina+cosa)/(tan^2a-1)=sina+cosa
2cos^2+3cos^a-2=0 求cosa .尽量写详细易懂一点 .
证明(1-cos^2a)/(sina-cosa)-(sina+cosa)/(tan^2-1)=sina+cosa
对于任意a属于(0,π/2) 比较sin(sina) sin(cosa) cos(a) cos(sina) cos(co
一道三角函数化简题化简:(1+sinA+cosA)[sin(1/2)A-cos(1/2)A]/根号(2+2cosA)(0
Sin^4a+Sina*Cosa+Cos^2a化简
已知sin a+cos a=1/2 sina*cosa=?cos a/sina+sina/cosa=?
cos^2a-sin^2a=(cosa+sina)(cosa-sina)吗?
已知sina+cosa=0,求sin^2a+2sinacosa+cos^2a
求证:1-cos^2a/sina-cosa - sina+cosa/tan^2a-1=sina+cosa