# Dear Dirichlet, Issue 07

Moonlighting agony uncle Professor Dirichlet answers your personal problems. Want the prof’s help? Send your problems to deardirichlet@chalkdustmagazine.com.

### Dear Dirichlet,

I’ve recently had the good fortune of winning three pigs at the village fete. However, I’m not sure whether my triangular garden is big enough for them as well as my collection of metal, wooden and other deckchairs. The pigs are of substantial size and my tape measure is not long enough to measure the longest side of the garden. I’ve also heard that pigs are very intelligent and would like to hear suggestions for entertaining them.

— Pearl among swine, Lower Brailes

# Prize crossnumber, Issue 07

Our original prize crossnumber is featured on pages 52 and 53 of Issue 07.

Clarification: Added “non-zero” to clues 10A, 19D.
Clarification: For 20D, 0 is not a factor of any number, so the number contains no 0s.

### Rules

• Although many of the clues have multiple answers, there is only one solution to the completed crossnumber. As usual, no numbers begin with 0. Use of Python, OEIS, Wikipedia, etc. is advised for some of the clues.
• One randomly selected correct answer will win a £100 Maths Gear goody bag. Three randomly selected runners up will win a Chalkdust t-shirt. The prizes have been provided by Maths Gear, a website that sells nerdy things worldwide, with free UK shipping. Find out more at mathsgear.co.uk
• To enter, submit the sum of the across clues via this form by 1 August 2018. Only one entry per person will be accepted. Winners will be notified by email and announced on our blog by 19 August 2018.

# e to thee x

I’m e,
If you don’t know me
I live
Between 2 and 3.

This is my story.

I’m misunderstood.
Everyone thinks I’m just 2.71
But there is more to me
That they don’t see
I wish they would.

And I’m named after a letter
Which makes things worse!
The other numbers laugh at me for that too.

So I say to them—look at the things I can do,
I mean, surely I’m the only number
To have walked this earth
And expressed themselves in verse?

But that’s not cool, that’s not fashionable,
It’s all about being able to
Express yourself as something fractional, instead.

Otherwise they say there is something wrong with you
You’re crazy,
Irrational.

Natural numbers can count themselves
Lucky.
They can easily find their space
Because our place
On that line
Is defined
By our digits
And I don’t know all of mine.

But there was a time
When there were three of us who didn’t fit.
Pi also didn’t know,
Exactly where to stand, or sit,
And next was i,
She was in a dimension of her own!

I thought the three of us
Were meant to be,
We were all part of the same identity.

But then we grew up.

I started to see Pi from a new angle,
I loved that rest of her body was basically a rectangle.

We went on a couple of dates.

But then came Pi Day:
Three, Fourteen.
She let them approximate her!

And she became
An overnight sensation,
A household name,
One of those faces
Everyone knows.

And lost in that world of meaningless approximation
She wouldn’t let me take her to more than two places.

Time passed,
And even my old friend i and I grew apart,
Of age,
I began to see what others had told me
And I’d refused to believe:
i was imaginary!

You might be wondering what about Tau?
She is twice the number Pi will ever be,
But Pi and Tau they are similar
And for me it was all a bit familiar,
Tau, she’s just too Pi.

So that’s it, back to lonely me.
It was hard
And I’m not a negative number.

But then
I met her,
$x$.

She said ‘I’m $x$’,
I asked, ‘are you a multiplication sign?’
She laughed, ‘I get that all the time’,
‘No, I’m curly $x$,’
She said.

She’s curly $x$, she’s sort of curvy $x$,
But that’s not it,
I’m not one to make judgements
Based on digits or figures,
She’s different,
She’s fun.

And it’s true
I can’t always work her out
But I like that, too.
With her is where I always want to be,
I want her to be my unknown quantity!

So I wrote her a poem
‘e to thee $x$’,
(It was better than this).

She opened it, tentatively,
Aloud,
Other numbers could hear!
Never have I wanted so much
To just
Disappear.

e to thee $x$, this poem I’d written,
This part of myself I’d given
Was supposed to feel just right,
But it was the opposite
It was the inverse of natural
(Logarithm?)

Actually, that poem, didn’t happen.
I just dreamt that.
It’s the 21st Century
I sent her a Snapchat.

I sent it and then screamed inside
Until she read it, and she replied.

I won’t tell you what she said
But the bit that is etched in my head
Is the final line, a string of Xs.

The first was curly $x$,
That’s her name,
The rest were to say
She’d like to see me again.

And if you’re worried that what is essentially
Just did something unexpected to your heart,
Then shame on you!
Numbers can have feelings too.

So this story is about me and $x$
And the number she’s shown me I can be,
I’m e, I live between 2 and 3,
I don’t know where exactly
I don’t care!

With $x$, I see things from a different view,
I laugh in the face
Of the quite frankly ridiculous number queue.

I’m me, I’m e!

# Prize crossnumber, Issue 06

Our original prize crossnumber is featured on pages 52 and 53 of Issue 06.

Correction: The pdf was incorrect and 5D did not match the clues below. This has now been fixed.
Clarification: Added brackets to 29A and 34D to reduce ambiguity.

### Rules

• Although many of the clues have multiple answers, there is only one solution to the completed crossnumber. As usual, no numbers begin with 0. Use of Python, OEIS, Wikipedia, etc. is advised for some of the clues.
• One randomly selected correct answer will win a £100 Maths Gear goody bag. Three randomly selected runners up will win a Chalkdust t-shirt. The prizes have been provided by Maths Gear, a website that sells nerdy things worldwide, with free UK shipping. Find out more at mathsgear.co.uk
• To enter, submit the sum of the across clues via this form by 8 January 2018. Only one entry per person will be accepted. Winners will be notified by email and announced on our blog by 22 January 2018.

# Dear Dirichlet, Issue 06

Moonlighting agony uncle Professor Dirichlet answers your personal problems. Want the prof’s help? Send your problems to deardirichlet@chalkdustmagazine.com.

### Dear Dirichlet,

I’ve just started my PhD at a well-known university, and I’m trying to make some friends. There are supposed to be 55 other students but nearly everyone in the PhD office refuses my offers of tea, sits in silence, and will barely talk to me unless I whisper them some very specific technical questions. I was hoping there would be some people in the group who enjoy everyday things: biscuits, beer, and just shooting the breeze. Is this really what academia is like?

— Pearl among swine, Withheld

# Prize crossnumber, Issue 05

Our original prize crossnumber is featured on pages 58 and 59 of Issue 05.

### Rules

• Although many of the clues have multiple answers, there is only one solution to the completed crossnumber. As usual, no numbers begin with 0. Use of Python, OEIS, Wikipedia, etc. is advised for some of the clues.
• One randomly selected correct answer will win a £100 Maths Gear goody bag. Three randomly selected runners up will win a Chalkdust t-shirt. The prizes have been provided by Maths Gear, a website that sells nerdy things worldwide, with free UK shipping. Find out more at mathsgear.co.uk
• To enter, submit the sum of the across clues via this form by 22 July 2017. Only one entry per person will be accepted. Winners will be notified by email and announced on our blog by 30 July 2017.

# Dear Dirichlet, Issue 05

Moonlighting agony uncle Professor Dirichlet answers your personal problems. Want the prof’s help? Send your problems to deardirichlet@chalkdustmagazine.com.

### Dear Dirichlet,

I personally have a very deep, long-held belief in free-market capitalism and the value of hard work, but I was recently shocked to discover when I switched subjects that most people in my new research area are staunch followers of Karl Marx! I’ve had many arguments with my new colleagues on this. I can feel my energy slowly draining with every passing debate. How do I resolve this?

— Feeling blue, Surreyv