正弦函数是奇函数，正弦函数y=sinx是奇函数，正切函数y=tanx是奇函数，余切度函数y=cotx是奇函数，余割函数y=cscx是奇函数。正弦=在直角三角形中，任意一锐...
我最喜欢的节日——春节 Spring Festival, also known as Chinese New Year, is my favourite festival. It holds a significant place in Chinese culture an...
