sine term

例句：

1. 1.The sine term of a trigonometric function is the argument that gives the function its shape.
   正弦项是三角函数的参数，它决定了函数的形状。
2. 2.In engineering, the sine term represents the amplitude of a wave.
   在工程学中，正弦项代表波的振幅。
3. 3. The sine term is used to calculate the phase shift in a system.
   正弦项用于计算系统相位偏移。