弦形曲线是高中数学教学中的一个难点,其中的曲线的变换更是难以理解,变化形式多样,题型也变换不穷。本文将应用教学构建观,利用构建观的方法让学生寻找图像变化规律,并且还严格规定了正弦曲线的定义,对于非严格的正弦曲线用简化了的公式给出了相应的转换方法。这样学生就能对形态各异的图像变化有了更深刻的认识,也便于把握。 String-shaped curve is a difficult point in high school mathematics teaching, the transformation of the curve is more difficult to understand, the diversity of forms of change, and the type of questioning are not bad. This article will use teaching to construct concept, use the method of constructing concept to let students look for the law of image variation, and also strictly define the definition of sinusoid. For the non-strict sine curve, the corresponding conversion method is given by the simplified formula. In this way, the students can have a deeper understanding of the morphological changes in images and are also easy to grasp.