1·This one is a hyperbolic parabloid.
这个曲面是一个双曲抛物面。
2·The hyperbolic trigonometric functions are to hyperbolae as the trigonometric functions are to circles. That is, imagine you plot these points on a Cartesian plane for all possible values of t.
双曲三角函数就是对曲线应用三角函数，也就是说，想象将这些点放在笛卡尔平面上来得到t的所有可能值。
3·Another reason why hyperbolic tangent is a good choice is that it's easy to obtain its derivative.
另一个原因双曲正切是一个很好的选择是很容易得到它的导数。
4·Returns the hyperbolic tangent of the specified Angle.
返回指定角度的双曲正切值。
5·The bounded solutions of non hyperbolic internal dynamics are discussed.
文中讨论了一类非双曲内部动态有界解的存在性。