As a parameter x=asinht (hyperbolic sine function), hyperbolic sine and cosine functions have the following properties:

(sinh t)'=cosh t，(cosh t)'=sinh t

2 kosh? t=cosh(2t)+ 1，sinh2t=2sinh t cosh t

X=0→t=0, x=a, t=arcsinh 1 recorded as α, dx=ad(sinh t)=acosh t, the original integral can be changed to

Sinhα= 1，

, using sinh t to define the inverse solution of α:

So the result of integration is:

According to the whole function even function

The end result is

This question can also be changed to x x=atan t.

(14) Use rounding difference method: