
Why is $1/i$ equal to $-i$? - Mathematics Stack Exchange
May 11, 2015 · Why is 1/i 1 / i equal to −i i? Ask Question Asked 10 years, 8 months ago Modified 1 year ago Viewed 116k times
factorial - Why does 0! = 1? - Mathematics Stack Exchange
Possible Duplicate: Prove 0! = 1 0! = 1 from first principles Why does 0! = 1 0! = 1? All I know of factorial is that x! x! is equal to the product of all the numbers that come before it. The product …
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Formal proof for $ (-1) \times (-1) = 1$ - Mathematics Stack …
Jun 13, 2020 · Is there a formal proof for $(-1) \\times (-1) = 1$? It's a fundamental formula not only in arithmetic but also in the whole of math. Is there a proof for it or is it just assumed?
If $A A^{-1} = I$, does that automatically imply $A^{-1} A = I$?
Mar 30, 2020 · 1 Short Answer Yes AA -1 = A -1 A = I when the Det (A) ≠ ≠ 0 and A is a square matrix. Long Answer A matrix is basically a linear transformation applied to some space. For …
What is the value of $1^i$? - Mathematics Stack Exchange
Aug 30, 2010 · The formal moral of that example is that the value of 1i 1 i depends on the branch of the complex logarithm that you use to compute the power. You may already know that 1 …
What does $QAQ^{-1}$ actually mean? - Mathematics Stack …
Apr 28, 2020 · I'm self-learning Linear Algebra and have been trying to take a geometric approach to understand what matrices mean visually. I've noticed this matrix product pop up repeatedly …
Proof that $(AA^{-1}=I) \\Rightarrow (AA^{-1} = A^{-1}A)$
How do you have A − 1 defined? Is A a square matrix? It is in general not true for nonsquare matrices that if AB = I that BA = I, so the fact that A is square must come into play somehow in …
How can 1+1=3 be possible? - Mathematics Stack Exchange
Feb 3, 2021 · So that's the "proof". The failure is at step 5, where you say that pq = pr p q = p r implies that q = r q = r; that's true only if you know p p is nonzero. For instance 0 ⋅ 5 = 0 ⋅ 7 0 5 …
abstract algebra - Prove that 1+1=2 - Mathematics Stack Exchange
Jan 15, 2013 · Possible Duplicate: How do I convince someone that $1+1=2$ may not necessarily be true? I once read that some mathematicians provided a very length proof of $1+1=2$. Can …