Question

已知角a的终边经过点P（5,-12）求tana的值,sin（a+π/6）的值

Answer 1

如果角a的顶点在原点,且另一边为x轴的话,tan a = -5/12sin a = -12/13,cos a = 5/13sin π/6 = 1/3,cos π/6 = √3/2sin(a+π/6)=(-12/13)(√3/2)+(1/3)(5/13)=-12√3/26+5/39=5/39-12√3/26=10/78-36√3/78=(10-36...