What is the purpose of Jordan Canonical Form?
news

What is the purpose of Jordan Canonical Form?

I don't claim at all to be an expert on this topic. In many (advanced) linear algebra textbooks for undergraduates, I usually find something about th...

Published: Sep 04, 2026

Could you please explain why the remainder when the square of 49 is divided by the square root of 49 is 0?
updates

Could you please explain why the remainder when the square of 49 is divided by the square root of 49 is 0?

Here is the original question, What is the remainder when the square of 49 is divided by the square root of 49? According to UKMT, Because 49 = 7×7, it fo...

Published: Sep 04, 2026

If $2^n+1$ is prime, why must $n$ be a power of $2$?
general

If $2^n+1$ is prime, why must $n$ be a power of $2$?

A little bird told me that if $2^n+1$ is prime, then $n$ is a power of $2$. I tend not to trust talking birds, so I'm trying to verify that statement...

Published: Sep 04, 2026

How many 4 letter words can we make from BANANAS
news

How many 4 letter words can we make from BANANAS

As the title suggests, I want to know the value of possible permutations without repetition given the word BANANAS BA1N1A2N2A3S so for example to word A1N...

Published: Sep 04, 2026

Row reduced $2\times3$ echelon matrices
general

Row reduced $2\times3$ echelon matrices

Suppose $R$ and $R'$ are two $2\times3$ row reduced echelon matrices if $RX=0$ and $R'X$ have axactly same solutions then prove that $R=R'$...

Published: Sep 04, 2026

Pure (sub)module (in $M$)
news

Pure (sub)module (in $M$)

What is the difference between a pure module $P$ and a pure module $P$ in a module $M$ ? I have a slight intuition though, what is the relationship betwee...

Published: Sep 04, 2026

Help me understand a 3d graph
updates

Help me understand a 3d graph

I've just seen this graph and while it's isn't the first 3d graph I've seen, as a math "noob" I never thought how these graphs are plo...

Published: Sep 04, 2026

How to calculate the amplitude and phase of such a complex expression?
updates

How to calculate the amplitude and phase of such a complex expression?

I got an expression like this: $a*\sin(x)+b*\cos(x)+i*c*\sin(x)+i*d*\cos(x)$. I want to calculate the amplitude and the phase of it. Can someone give me s...

Published: Sep 04, 2026

The expression $\sqrt{13+3\sqrt{\frac{23}{3}}} +\sqrt{13-3\sqrt{\frac{23}{3}}} $ is which type of number?
news

The expression $\sqrt{13+3\sqrt{\frac{23}{3}}} +\sqrt{13-3\sqrt{\frac{23}{3}}} $ is which type of number?

(a) A natural number, (b) A rational number but not a natural number, (c) An irrational number not exceeding 6, (d) An irrational number exceeding 6. Plea...

Published: Sep 04, 2026

What do you call a 3D annulus/cylindrical shell and parts of it?
updates

What do you call a 3D annulus/cylindrical shell and parts of it?

Take a cylinder and punch a centered circular hole through it--like a washer. What is that shape called? In 2D it's an annulus, but what's the n...

Published: Sep 04, 2026

Trending