SINE

例句：

1. 1. The angle of the sun at noon is always a right angle.
   中午时太阳的角度总是直角。
2. 2. The sine wave has been used to create music and other sounds.
   正弦波已被用于创造音乐和其他声音。
3. 3. The sinusoidal waveform shows a constant frequency and amplitude.
   正弦波形显示恒定的频率和振幅。