题目内容：

如图,角a的顶点在直角坐标系的原点,一边在x轴上,另一边经过点p(2,2倍根号3)
,求角a的三个三角形函数值

优质解答

从P向x轴做垂线,垂足B(2,0)
OB = 2,OP = √[2² + (2√3)²] = 4,BP = 2√3
sina = BP/OP = 2√3/4 = √3/2
cosa = OB/OP = 2/4 = 1/2
tana = BP/OB = 2√3/2 = √3