∵cos(派/6 -阿尔法）+sin阿尔法=五分之四倍根三∴ cos(π/6)cosα+sin(π/6)sinα+sinα=4√3/5∴ (√3/2)cosα+(3/2)sinα=4√3/5∴ √3sinα+cosα=8/5∴ sin(α+7π/6)=-sin(α+π/6)=-[sinαcos(π/6)+cosα*si...