双曲函数<br>这是最常见的三个双曲函数:<br>sinh、cosh 和tanh<br>(就是双曲正弦、双曲余弦和双曲正切)<br>sinh x =ex− e−x2<br>cosh x =ex+ e−x2<br>tanh x =sinh xcosh x=ex− e−xex+ e−x<br>导数<br>这些函数的导数是:<br>ddxsinh x = cosh x<br>ddxcosh x = sinh x<br>ddxtanh x = 1 − tanh2x