390 Quick
Answers 3 March
Exam
topics? Remember the exam is sooner than you think (3
classes from now). Friday will be the last day for material
on the exam. Someone asked - yes, you may use examples that
I don’t discuss in class. 1600 is a decent cutoff for the
exam.
Also
of course remember your annotated bibliography is due by classtime
on Friday. It must be in .pdf to get formatting correct. Oh,
and _one_ paragraph to wrap together. One per source to wrap
together makes no sense. Those who will present at GREAT Day
need a title and abstract for Monday. A catchy but on-topic
title is appropriate. The abstract should be a description
of what you’re going to talk about, it should not be everything
that you’re going to say about it. It should make sense to
other math. majors.
Again
we will have some delay. I will finish some 6.1 material on
Friday, but will do all of 6.2 then also. 6.2 is a bit
light. I’m pushing quartics and complex to Friday.
Again, be careful on timing between 6.1 and 6.2.
I have a question … when I put individual comments to you in your
my-learning submission - do you see them?
Lecture
Reactions
Again,
just because you use combinatorics in probability, does not mean
it _is_ probability or statistics. Arithmetic is not
calculus, but it is used in calculus. We have discussed no
probability nor statistics … although Cardano was a first for
probability, and we will discuss him today.
ben Gerson was not the first to use induction, al Karaji did about
200 years before. It is reasonable to believe the two were
independent, and neither caught on very much at the time, I
think. Why did I focus on ben Gerson and not al
Karaji? I don't have a good answer - but we were rather busy
during Islamic work, and less so in chapter 5.
I think Oresme's work with ratios is a step toward working more
with fractions than ratios, which is more what you are familiar
with. We have seen in our original source work that before
this it was more discussed in terms of ratios.
Graphing
as we saw in Oresme is new and a _big deal_. Notice we
have graphs long before coordinates. That will be another
big deal. Graphs are plotting points at heights
perpendicular to a base.
One
theme of last class was the question of how influential a
mathematician is. Clearly since we don't use his notation,
Chuquet wasn't very influential. To be clear, I don't know
of any others referring to his work or style. He didn't
have the audience. There are many other similar
stories. We see them from time to time. It is very
fair to say that Chuquet was comfortable with the rule for
multiplying two powers of the same base. Chuquet used a
dot with an exponent where you would write an x.
We still have no equations, and basically none of our
notation. Lots of words. You'll see a little today of
original pre-translated sources. They will start to look
more familiar in the next couple classes. Watch
carefully. The writing we see is matched in their
work. They are not secretly using mathematical
notation. Keep this in mind in our work today and next time
especially.
Why do we skip 140 years? I think it's fair to say that
Europe is still waking up.
Reading
Reactions
Quarantine
means forty and references the biblical 40 days, but the first use
for disease was for 30 days. That is the best of my
understanding of a somewhat complicated situation.
Jeff is probably overreacting to mathematics going from _all_ of
the liberal arts. In particular, it sounds as if he is a
showing a little personal grudge there. There's no real
downgrade in Renaissance times, if anything, it is rising again,
as we see.
How do languages get to be "the language of science"? Good
question to which I don't have a good answer … it has generally gone
from Greek, to Arabic, to Latin, to French, to English, as far as I
know.
del
Ferro was the first to solve cubics algebraically. He taught
Fiore. Tartaglia (Niccolo Fontana) devised it
independently. Cardano probably stole from Tartaglia, then
found del Ferro’s notes and claimed that he knew from them.
That’s the short version. Jeff tells the longer version
better. Yes, it’s all true. The mathematics we will
discuss is mostly del Ferro’s method. We'll see some
narrative from this tale. I think it's fair to say this is
the first big priority dispute. Oh, and I said we would
notice when people start to want credit. We're there.
Finally, if your livelihood relies on you solving problems in
competitions, you want to not tell others how you do it.
"Cosa" is the Italian word for "thing", which was used as the
variable.