如何计算负数的平方根？ [英] How to compute the square root of negative numbers?

问题描述

我正在尝试使用以下代码从负数的平方根创建复数：

I'm trying to create a complex number from the square root of a negative number using the following code:

 include Math
 z = Complex(sqrt(-9))

但是它会产生此错误： / p>

But it produces this error:

Math::DomainError: Numerical argument is out of domain - "sqrt"
    from kata2.rb:20:in `sqrt'
    from kata2.rb:20:in `polinomio'
    from kata2.rb:34
    from /home/howarto/.rvm/rubies/ruby-2.0.0-p247/bin/irb:13:in `<main>'

如何从负数的平方根构建复数？

How can I build a complex number from the square root of a negative number?

推荐答案

数学。 sqrt 函数无法计算负数的平方根：

The Math.sqrt function can't compute the square root of negative numbers:

irb> Math.sqrt(-1)
Math::DomainError: Numerical argument is out of domain - "sqrt"
...

您必须使用 CMath 模块，可根据需要返回复数：

You have to use the CMath module that return complex numbers as needed:

irb> require 'cmath'
irb> CMath.sqrt(-1)
# => (0+1.0i) 
irb> CMath.sqrt(-1).class
# => Complex
irb> CMath.sqrt(1).class
# => Float

这篇关于如何计算负数的平方根？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！