作正(余)弦型函数y=Asin(ωχ+ )[y=Acos(ωχ+ ),其中A≠0,ω≠0]的图像是取可确定大致形状的五点来作的.利用类比推理的方式,我们考虑确定正(余)切型函数y= The positive (co) string function y = Asin(ω χ + )[y = Acos(ω χ + ), where A ≠ 0, ω ≠ 0] is obtained by taking five points that can determine the approximate shape. In the way of reasoning, we consider determining the positive (co)-cut function y=