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10:13
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Q: Struggling with iota in log. What's wrong in solution please tell.

Siddhant GujarIn my solution ln1 =- 4 (π/2+2nπ)i Is it correct or what wrong in it.[image][1] ln1=ln1/1 =ln(1/i)⁴ =-4lni i is e^i(π/2+2nπ) So -4lni is ln1 is -4ln(e)^i(π/2+2nπ) So ln1 is -4(π/2+2nπ) [ \ln 1 = \ln \frac{1}{1} = \ln \frac{1}{(i)^4} = 4 \ln i^{-1} = 4 \ln i^1 = -4 \ln i ] [ i = e^{i \left(\frac{\...

$i$ is not an iota. And yes, it is wrong, although close to right, assuming you are using a mu;to-valued function.
What's mu;to function. I m not that much good at math
That was a typo, "multi-valued" was what I meant.
But what's wrong in the solution? Is ln1 equal to -4 (π/2+2nπ)i and what it meant by i is not iota
Well, those are some of the values for $\log 1.$ But it is a strange way to write even those, and there are are lots of other values.
Iota is a Greek letter, and $i$ is not a green letter.
10:13
$\ln 1 = \ln 1^{-4} = -4 \ln 1$ so $5\ln 1 =0$ and therefore $\ln 1 = 0$.
From where did you take 5ln1=0?
@CyclotomicField That rule for $\ln(x^n)$ is not true for complex numbers.
Thomas can you please show what is the basic mistake means X ^n why we can't take out in complex how to prove that as like √ab≠√a√b if both are negative.
@ThomasAndrews I'm referring to the mistake he made in his calculation. He adds a factor of $i$ incorrectly.
If $x = -4x$ then $5x=0$ and so $x=0$. Now just put $\ln 1$ in for $x$.
You haven't shown how you got your result, so I can't tell you what your mistake is. But $0$ is one value of $\ln 1,$ and it is not covered by your formula.
I'm not trying to read an image.
10:13
The mistake is that $4 \ln \frac11 = -4 \ln 1 \neq -4\ln i$.
Cyclotomicfield( -4 ln i )not -4ln1
Thomas please see image
What's wrong in the question why question is deleted
What's wrong in the question why it is being deleted!
It's not deleted, it is closed. Your question should be self-contained, and not rely on images. You can edit your question and request it be reopened.
Ohhh ok i changed it
Please read a MathJax tutorial for clearer formatting, first.
Hey how to type mathematically any video for that.... On this website how to type I'm new here
10:13
For MathJax, you can start by looking at math.stackexchange.com/help/notation and follow the links for any additional techniques you need.
@CyclotomicField The question isn't about $\ln (1^{-4}),$ it's about $\ln( i^{-4}).$ And of course $i^{-4}=1.$ The error is the assumption that $-4\ln z$ is always the value (and the only value) of $\ln(z^4)$ where $z$ is an arbitrary complex number.

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