Math.asinh()

x

一个数值。

返回指定数值的反双曲正弦值。

由于 asinh() 是 Math 的静态方法,所以应该像这样使用：Math.asinh()，而不是作为你创建的 Math 实例的方法（Math 不是一个构造函数）。

As a quick and dirty hack the expression $\operatorname {arsinh} (x) = \ln \left(x + \sqrt{x^{2} + 1} \right)$ may be used directly for a coarse emulation by the following function:

Math.asinh = Math.asinh || function(x) {
  if (x === -Infinity) {
    return x;
  } else {
    return Math.log(x + Math.sqrt(x * x + 1));
  }
};

Been formally correct it suffers from a number of issues related to floating point computations. Accurate result requires special handling of positive/negative, small/large arguments as it done e.g. in glibc or GNU Scientific Library.

• Math.acosh()
• Math.atanh()
• Math.cosh()
• Math.sinh()
• Math.tanh()