化简:[cos(α-5π)+2sin(3π-α)]/[csc(3π+α)+sec(5π+α)]
问题描述:
化简:[cos(α-5π)+2sin(3π-α)]/[csc(3π+α)+sec(5π+α)]
答
[cos(α-5π)+2sin(3π-α)]/[csc(3π+α)+sec(5π+α)]=[cosacos5π+sinasin5π+2(sin3πcosa-cos3πsina)]/[1/sin(3π+a)+1/cos(5π+a)]=[-cosa+2sina]/[-1/sina-1/cosa]=(-cosa+2sina)*sinacosa/(-cosa-sina)=(-1...