Entire extension of the Fouier transform of a smooth compactly supported function
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Entire extension of the Fouier transform of a smooth compactly supported function

The statement which is not very clear is this: if $\phi \in C^{\infty}_0$ then its Fourier transform extends to a complex-analytic function. Of course the...

Published: Aug 23, 2026

Find the angle between two planes using their normal vectors
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Find the angle between two planes using their normal vectors

The angle between two intersecting planes is defined to be the angle between their normal vectors. Find the angle between the planes $x – 2y + z = 0$ and ...

Published: Aug 23, 2026

Finding the largest possible delta in a epsilon-delta limit?
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Finding the largest possible delta in a epsilon-delta limit?

$$\lim_{x\to0}\frac{x^2+2x}{x^2-3x} = - \frac{2}{3}$$ Given that $\epsilon = 0.01$, what is the largest possible $\delta$ according to the epsilon-delta d...

Published: Aug 23, 2026

The product of any number and zero is zero
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The product of any number and zero is zero

I don't understand why this proof is valid. The proof just swaps the left and right hand side of the equality. Is this a valid method of proof for eq...

Published: Aug 23, 2026

Can I conjugate a complex number : $\sqrt{a+ib}$?
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Can I conjugate a complex number : $\sqrt{a+ib}$?

Can I conjugate a complex number: $\sqrt{a+ib}$ ? Actually my maths school teacher says and argues with each and every student that we can't conjugat...

Published: Aug 23, 2026

Measuring angles in the Beltrami Klein model of Hyperbolic geometry
general

Measuring angles in the Beltrami Klein model of Hyperbolic geometry

I am learning bits of hyperbolic geometry and the wikipedia page gives two such standard models for it ; the Beltrami Klein (BK) model and the Poincare (P...

Published: Aug 23, 2026

How do I rotate a vector 90 degrees in a random direction?
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How do I rotate a vector 90 degrees in a random direction?

I'm building a tree generator and I'm at the point where I want to have sub branches branch off at right angles off the current branch, in rando...

Published: Aug 23, 2026

How is this true? Bookworm puzzle
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How is this true? Bookworm puzzle

This is from Eugene Northrop's book Riddles in Mathematics. Why is the answer 1 inch. Iit should be three. What logic am I missing here?

Published: Aug 23, 2026

Finding all left inverse of a matrix B
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Finding all left inverse of a matrix B

Let $$ \mathbf{B} = \left[\begin{array}{cc} 0 & 1 \\ 1 & -3 \\ 0 & 0 \end{array}\right]. $$ My task at hand is to all left-inverse matrices of...

Published: Aug 23, 2026

What needs to be done to prove that a vector bundle is trivial?
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What needs to be done to prove that a vector bundle is trivial?

What needs to be done to prove that a vector bundle is trivial? equivalently, This can be thought of as proving that the vector bundle satisfies the crite...

Published: Aug 23, 2026

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