### more tales out of school

my recent example of bad freshman calculus
was, heaven knows, something egregious.
but *this*! this is something else again.

on another day, i might have just bitten down
and let it go with full credit… the very
kind of thing i have to do dozens of times
a night when i sit down to earn my right
to go on calling myself a math teacher.

will *never* be made in classes like ours
to write carefully. and they’ll take any
attempt to do it as a violation of their
basic civil rights *as* undergrads and
threaten to vote with their feet.
so you’ve got to play it pretty cool.
even though it might break your heart.

just mark it wrong, again.
and tell ‘em why, again.
“CODE IS NOT ENGLISH”
usually doesn’t get points-off
*regardless* of how badly the little
dears have mangled plain sense into
worse-than-meaningless mumbo-jumbo
by using “syncopated style”.

but this example, on this day?
i just couldn’t do it. its author
lost a half a point (out of two).

“f(x) = log_a x = (ln x)/(ln a)
f'(x) = 1/(ln a) * 1/x” …
thus far well and good …
“since the derivative of ln x = 1/x”.

and my first instinct, and indeed my
first move, is to circle the “=”,
write “IS” near it, put a big “X” near
the whole mess so far, and write out
“CODE IS NOT ENGLISH”.
and let it go at that.
like usual.

but, finally, dammit.

if that thing deserves a perfect score
then i’m carl friedrich gauss.

if i *ever* encounter “ln x = 1/x”
*without* letting it bother me,
may my right hand lose its cunning.
take away my mathbooks and send me
to seminary or something; i’ll’ve
quit being a *math* teacher altogether.

the student in question will almost certainly
take my comments for raving lunacy. and so,
i suppose, will some portion of readers of this
post. none of *my* business either way, though,
i suppose. sometimes you’ve just gotta get up
on the net and *vent*. thanks for reading.

1. suevanhattum

I agree with your previous rant, but not this one. Instead of ‘is’, I’d have added parentheses to make it right … (derivative of ln x) = 1/x. (And maybe no points off. If I know what they mean, then they’ve succeeded in communicating.)

2. i kind of like your alternative
correction… for a lower-level class.

it’s time-and-a-half *past*
time *these* folks were
my being able to guess
what they were getting at
counts for *nothing*: the
*entire point* of all our
efforts is that they will
learn and use the *proper*
symbols in the *right* order
to say very *precisely* how
they’ve solved the exercises.

this is analysis.
f_n,
f_n(x),
(f_n),
and
(f_n(x))
have *four different meanings*
(a function, a number,
a sequence-of-functions,
and a sequence-of-numbers).

students unwilling to make such
distinctions have *missed the point*
of the entire process, period.
we *cannot discuss our subject*
in any useful way *without*
making these distinctions.
in good clear writing.

same thing here.
respect the “equals” sign or begone.
this is the temple of reason not
some tailgate party.

3. anyhow, let me emphasize that i usually
*don’t* dock ‘em for suchlike ghastly slop.

just, this “log is reciprocal” thing.
it’s like they’re dissing my motherland.
when it hurts this much, if i *didn’t*
make a fuss, i’d have to be some
sort of enemy *spy*.

“log is reciprocal” error, of course.
just… that… one… particular…
dirty… lying… *non-equation*
just smacked me and called me
a dirty name.

i *know* it can’t be made to stop.

and it’s better to light a single candle
than to curse the darkness.
but… why not both?

• ## (Partial) Contents Page

Vlorbik On Math Ed ('07—'09)
(a good place to start!)