MHB Imaginary Part of a Complex Function: How to Find It?

  • Thread starter Thread starter Poly1
  • Start date Start date
  • Tags Tags
    Imaginary
AI Thread Summary
To find the imaginary part of the function $\frac{1}{i}xe^{-ix}+e^{ix}$, the first term can be rewritten using a negative exponent for $i$, applying the property $i^{n}=i^{n+4k}$. The second term utilizes Euler's formula, which states that $e^{\theta i}=\cos(\theta)+i\sin(\theta)$. After correcting a missing $i$ in the calculations, the user successfully derived the answer. The discussion highlights the importance of understanding complex exponentials and their relationship to trigonometric functions. Overall, the method effectively illustrates how to extract the imaginary part of complex functions.
Poly1
Messages
32
Reaction score
0
How do I find the imaginary part of $\displaystyle \frac{1}{i}xe^{-ix}+e^{ix}$?
 
Last edited:
Mathematics news on Phys.org
For the first term, I would rewrite i with a negative exponent, then apply:

$\displaystyle i^{n}=i^{n+4k}$ where $\displaystyle k\in\mathbb{Z}$

For the second term, apply Euler's formula:

$\displaystyle e^{\theta i}=\cos(\theta)+i\sin(\theta)$
 
Sorry there was an $i$ missing from the first part. But I got the answer using your suggestion. Thanks.
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
Suppose ,instead of the usual x,y coordinate system with an I basis vector along the x -axis and a corresponding j basis vector along the y-axis we instead have a different pair of basis vectors ,call them e and f along their respective axes. I have seen that this is an important subject in maths My question is what physical applications does such a model apply to? I am asking here because I have devoted quite a lot of time in the past to understanding convectors and the dual...
Thread 'Imaginary Pythagoras'
I posted this in the Lame Math thread, but it's got me thinking. Is there any validity to this? Or is it really just a mathematical trick? Naively, I see that i2 + plus 12 does equal zero2. But does this have a meaning? I know one can treat the imaginary number line as just another axis like the reals, but does that mean this does represent a triangle in the complex plane with a hypotenuse of length zero? Ibix offered a rendering of the diagram using what I assume is matrix* notation...

Similar threads

Replies
5
Views
2K
Replies
13
Views
271
Replies
1
Views
1K
Replies
2
Views
3K
Replies
11
Views
2K
Back
Top