Is x^pi Real for Negative Values of x?

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In summary, the functions x^pi and x^e are real for x≥0 only. When examining these functions in the interval for both odd and even functions, there is no noticeable difference in their shape. Therefore, pi is not an odd number according to the definition of an odd number n=2k+1 for some integer k. This is true because when taking some positive number x, (-x)^pi equals (-1)^pi times x^pi. Since x is positive, x^pi is greater than 0, and we only have to consider the (-1)^pi factor. However, this factor is complex and cannot be a real number. This can be proven by converting it into its complex form and ded
  • #1
cstvlr
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The plot of x^(pi) looks like an odd function, does that make pi an odd number?

http://www.wolframalpha.com/input/?i=x^pi

same goes for x^e

http://www.wolframalpha.com/input/?i=x^e
 
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  • #2
Those functions are real for [tex]x\geq 0[/tex] only. If you take a look at that interval for both odd and even functions, you'll realize that you can't really tell a difference between their shape.
And no it doesn't make pi an odd number.
 
  • #3
the definition of an odd number n is a number that's able to be expressed as n=2k+1 for some integer k. use that definition to see if pi is an odd number.
 
  • #4
Mentallic said:
Those functions are real for [tex]x\geq 0[/tex] only. If you take a look at that interval for both odd and even functions, you'll realize that you can't really tell a difference between their shape.
And no it doesn't make pi an odd number.
why is that true?
 
  • #5
mxbob468 said:
why is that true?

Because if we take some positive number x, then [tex](-x)^{\pi}=(-1)^{\pi}\cdot x^{\pi}[/tex]
Since x is positive, [tex]x^{\pi}>0[/tex] so we just have to deal with the [tex](-1)^{\pi}[/tex] factor. It is complex, but if you want a proof of this, simply convert it into its complex form:

[tex]e^{i\pi}=-1[/tex] therefore [tex](-1)^{\pi}=e^{i\pi ^2}=cos(\pi ^2)+isin(\pi ^2)[/tex] so if it is to be a real number, then the sin of [tex]\pi ^2[/tex] needs to be equal to 0, but this isn't the case.

In fact we can take any power [tex]x^{\alpha}[/tex], and deduce the circumstances whether it will be real or complex for negative values of x by following a similar process. But be wary, it is a little more complicated dealing with all rational values.
 

Related to Is x^pi Real for Negative Values of x?

1. Is pi an odd number?

No, pi is not an odd number. It is an irrational number, meaning it cannot be expressed as a simple fraction, and it is also not a whole number.

2. Is e an odd number?

No, e is also not an odd number. Like pi, it is an irrational number and not a whole number.

3. Can pi or e be written as an odd number?

No, neither pi nor e can be written as an odd number because they are both irrational numbers and cannot be expressed as a fraction with odd numbers in the numerator and denominator.

4. Are there any odd numbers involved in calculating pi or e?

No, neither pi nor e involve odd numbers in their calculations. Pi is derived from the ratio of a circle's circumference to its diameter, and e is derived from a mathematical limit.

5. Why are pi and e not odd numbers?

Pi and e are not odd numbers because they do not fit the definition of an odd number. An odd number is any integer that is not divisible by 2, but pi and e are not integers and cannot be divided into equal parts.

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