# A Factor of Minus-One ~ math limericks by Marion Deutsche Cohen

### Some pre-calc

(binomial formula – for expanding (x + y)-to-the-n )

I’m sure you’re a most loyal FOIL-er
and I’ll never be a FOIL-spoiler
but when n, for its britch
gets too big, you should switch
and be to this formula loyaler.

(the non-minimum continuum)

Real numbers are squashed as can be.
They’re locked in and don’t have a key.
Howe’er in we zoom
there’s no elbow room
and even less room for a knee.

### Some calc

(implicit differentiation – e.g., xy’ + y = 2x, solve for y as a function of x)

We’ve x’s and y’s too galore.
So how can we tackle this chore?
Just diff regardless.
Perhaps it seems heartless
but mindless it isn’t, for sure.

### Linear algebra

(Every linear operator L equals left-multiplication by some matrix A)

Just take what L does to each e
and line them all up merrily.
Yes, that’s a good way
to get your big-A.
(Watch out so you don’t get a B.)

### Abstract algebra

(types of functions from one group to another)

A group theory pro named McClellan
said “too many isom and elem
“and homom and autom
“but already bought ‘em.
“Perhaps we could try to re-sell ‘em.”

### Classroom rapport in Advanced Engineering Mathematics classes

(I was often off by a minus-sign. – 3 episodes)

Our pretty professor’s a rarity
her lectures the summit of clarity
except that when
minus-one to the n
comes up, n is not the right parity.

Our pretty professor, that rarity
engulfed in such hyper-hilarity
‘cause again she has spun
a spare minus-one,
shrugs “Well, we can give it to charity.”

It’s Jan. 25 and out prof
by a factor of 2, now, is off.
Is she going to cry?
Says she “No, not I.
“in fact, I’m more likely to laugh.”

### Category theory

(product = projection-collection)

This hunter shoots many a spear
just one, though, to each object here.
And any who dare
to likewise fare
must take a quick step to the rear.

(Co-product = injection-collection)

The object of this grand old hunt
(don’t worry; the arrows are blunt.)
is, any who tries
to fare likewise
must take a quick step to the front.

(two for p-adic analysis – Are you a p-adic fanatic? Better yet, are you a p-addict?)

Another cool fact from your mentor:
A ball has much more than one center.
Indeed they are all
inside the ball.
To find them you need simply enter.

Another cool fact, please annex it.
To absentee buddies please text it.
The non-centers all
are outside the ball.
To find them you need simply exit.

### And to conclude …

(Google Russell’s paradox: The set of all sets that don’t contain themselves – does it contain itself? And Goedel’s incompleteness theorem: no sets of axioms can prove everything that’s true. So my History of Math student Yolanda called Russell and Goedel “two party poopers,” and this limerick is titled “Two Party Animals”)

I offer the following hunch.
(We’ll hash it all out over lunch.)
To say that these two
were poopers – not true.
I’d say they just spiked the ol’ punch.

Marion Deutsche Cohen is the author of 31 collections of poetry or memoir; her latest poetry collections are The Essence of Seventh Grade: A Kind of Autobiography (Alien Buddha Press), The Project of Being Alive (New Plains Press, AL), and The Discontinuity at the Waistline: My #MeToo Poems (Rhythm and Bones Press, PA). She is also the author of two controversial memoirs about spousal chronic illness, a trilogy diary of late-pregnancy loss, and Crossing the Equal Sign, about the experience of mathematics. She teaches a course she developed, Mathematics in Literature, at Drexel University, as well as a new course, Societal Issues on the College Campus. Other interests are classical piano, singing, Scrabble, thrift-shopping, four grown children, and six grands. Her website is marioncohen.net.

See other work by Marion Deutsche Cohen in The Disappointed Housewife here.

## One thought on “A Factor of Minus-One ~ math limericks by Marion Deutsche Cohen”

1. […] If you like math, and you like limericks, you’ll love Marion Deutsche Cohen’s “A Factor of Minus-One.” […]