如1.5 ** 2.5，如何计算？似乎是这样的：

1. cmath calculates pow(a,b) by performing exp(b * log(a)). *

2. 幂级数展开常用公式 CSDN Rqff

 3. 泰勒级数 百度百科

The Taylor series of a real or complex-valued function f (x) that is infinitely differentiable at a real or complex number a is the power series

where n! denotes the factorial of n. In the more compact sigma notation, this can be written as

where f(n)(a) denotes the nth derivative of f evaluated at the point a. (The derivative of order zero of f is defined to be f itself and (x − a)0 and 0! are both defined to be 1.)

When a = 0, the series is also called a Maclaurin series.