# Mathematical Mystery 2

I am all around your everyday life

But you can't see me with eyes, like a hidden knife

I am made up of some of the most important numerals in town

Just take away imagination and these irrational clowns

Name this mathematical concept

Hint 1

The first line is about computers and smartphones or any digital tech

Binary

Edit:

I am all around your everyday life

It's in your phone, it's in computers, it's in everything you use.

But you can't see me with eyes, like a hidden knife

You can't see the individual bits that computers use, but it is important, like a hidden knife.

I am made up of some of the most important numerals in town

Here the most important numerals are 0 and 1 (possibly i or e or pi could have claim to that position but the next line dissallows that)

Just take away imagination and these irrational clowns

We don't care about imaginary numbers and irrational numbers, thus leaving us with only 0 and 1

Name this mathematical concept

Binary is a mathematical concept

• Correct, now you just have to explain the lines – Xavier Stanton Aug 13 '18 at 22:06
• @XavierStanton If you can I'd accept nikki's answer, they corrected it and added the solution before me. – tox123 Aug 13 '18 at 23:31
• I do accept the answer, and it looks like an explanation is coming on mobile in a little bit – Xavier Stanton Aug 14 '18 at 0:36
• @tox123 This answer hasn't been sufficiently explained. You appear to have intended to update it, but never did. Can you elaborate on your answer, please? – GentlePurpleRain Nov 1 '18 at 16:10
• @GentlePurpleRain Oh wow I forgot, thanks for reminding me! – tox123 Nov 1 '18 at 22:57

Base system - binary?

I am all around your everyday life

In all digital works

But you can't see me with eyes, like a hidden knife

Can't really see the chips, they're too tiny

Most important numerals in town

0 and 1 are the numerals in binary town, 0... k-1 for town/system with base k

• No. The fourth line says that imaginary numbers and complex numbers aren't present here – Xavier Stanton Aug 10 '18 at 1:47

I think it's

I am all around your everyday life

Hexadecimals are used in electronics and digital memory

But you can't see me with eyes, like a hidden knife

Hexadecimal numbers are not directly visible, they're a group of 4 bits which in turn are electronic chips

I am made up of some of the most important numerals in town

Binary numbers are arguably the most important numerals and hexadecimal numbers are groups of four binary digits.

Just take away imagination and these irrational clowns

Hexadecimal numbers don't deal with irrational or imaginary numbers

• No, but it is a number system – Xavier Stanton Aug 13 '18 at 22:08

I was thinking along the lines of

$\mathbb{Q}$

Since

The third and fourth lines suggest the set of numbers without the complex and irrational numbers. Maybe also the second line (can't see it with eyes ($i$)).

• Unfortunately no, the hidden knife part is just for the rhyme – Xavier Stanton Aug 10 '18 at 3:15
• @XavierStanton Could you please point to the part of the question that makes this a wrong answer? If the only part is "that's not the answer I intended", then it would be a very good idea to add some more clues that explicitly exclude this answer. – Bass Aug 10 '18 at 6:53

Is it

sine?

I am all around your everyday life

as sound waves

But you can't see me with eyes, like a hidden knife

sound is not perceived with the eyes

Just take away imagination and these irrational clowns

Made me think of fourier transform which is applicable to sound. Remove the complex part and I guess you get the magnitude of sine waves?

• That is incorrect – Xavier Stanton Aug 10 '18 at 22:22

This is far-fetched, but are you maybe referring to a

derivative

It is all around because

differential equations are quite common in electronics

made up of some of the most important numerals in town

the definition of a derivative: lim, 0, f(x)... all important concepts

Not sure about the "imagination and these irrational clowns", but neither complex nor irrational numbers are closely related with the definition itself.

• Incorrect, but it is a good thought – Xavier Stanton Aug 13 '18 at 22:07

Is it

Euler's identity, exp(i*pi) + 1 = 0

I am all around your everyday life

Used all around us in laptops, phones etc for complex signal analysis

But you can't see me with eyes, like a hidden knife

There is the component i, which makes it imaginary

I am made up of some of the most important numerals in town

It involves e, pi, i, 1 and 0, the 5 fundamental concepts in Math

Just take away imagination and these irrational clowns

The RHS of the equation is 0, "taking away" i (imaginary) and pi (irrational)

• That is an amazing guess, but incorrect. You have to leave out e as well. It doesn't appear in the answer – Xavier Stanton Aug 10 '18 at 1:46