What the hell sci

>starting a degree in math and physics this fall
>in the meantime taking a summer course in discrete math for comp-sci majors at a local university
>professor says something about the sum of to rational numbers is always rational. one of the students asks if he can prove it, and the professor says "no, it's an axiom".
>mfw

he makes about 5-6 mistakes every lesson (especially logical fallacies) and everybody just eats it up.
is it like this in every math course for comp-sci majors? what would you do?

>inb4 *two* - it's a typo.

>What is a field
>What is closure

If it's a summer course it's possible that person is a lecturer and not a prof, basically he's a glorified cs undergrad, that's the problem. Also the sum of a finite number of rationals being a rational is not an axiom, it called fucking addition. The reason why people are eating it up is because they don't care nor do they understand the material. Not all comp sci math courses are like this though, mostly since they can't afford to fuck up basic discrete math since they'd be doubly fucked when trying to program that shit.

>>professor says something about the sum of to rational numbers is always rational. one of the students asks if he can prove it, and the professor says "no, it's an axiom".

Kind of, "axiom 0" of a group is closure. It's axiom '0' because you automatically get it from the binary operator +: GxG->G being defined into G.

>is it like this in every math course for comp-sci majors

Yes because they are brainlets.

He probably just brainfarted and meant to use another word instead of "axiom".

It's just a readily apparent result.

>one of the students asks if he can prove it

F.U.C.K

T.H.A.T

G.U.Y

A.N.D

H.I.S

D.E.M.E.N.T.E.D

Q.U.E.S.T.I.O.N.S

T.H.A.T

I.N.T.E.R.R.U.P.T

T.H.E

L.E.C.T.U.R.E

I always hated when kids would ask the teacher to prove something, or when the teacher would prove something. Takes like a fucking hour to prove the stupidest shit. I came to university to learn what, not how. Particularly since I'm a physicist who cares waaay more about if it works, than why it works.

Is this pasta?

No, I just really loved math class before people felt the need to prove it works. I go to school because I trust that it works. You could learn at least twice as much if you didn't waste time on proofs.

For the discrete math class I took the whole point was to use and learn proofs for different parts of mathematics. I would have hoped the prof. would have given you the proof upfront anyway for that statement.

Like, I get the point of it in a math class for mathematicians. Just most courses/people in them aren't geared towards studying Math as a subject, just math as a tool. Maybe they need to divide math courses into theoretical courses and practical courses, like any other field.

>professor says something about the sum of to rational numbers is always rational. one of the students asks if he can prove it, and the professor says "no, it's an axiom".
Writing a proof takes literally less than a minute.

Let [math]a, b, c, d \in \mathbb{Z}[/math] where [math]b, d \neq 0[math].

Now, [math]\frac{a}{b} + \frac{c}{d} = \frac{ad}{bd} + \frac{cb}{db} = \frac{ad + cb}{bd}[/math],

which is a rational number since [math]ad + cb \in \mathbb{Z}[/math], [math]bd \in \mathbb{Z}[/math] and [math]bd \neq 0[/math].

prove that multiplication of integers is integer

prove that summation of integers is integer

Prove that I didn't fuck your mother last night.

I don't know about your uni but mine has the distinction between applied mathematics and pure mathematics. Apart from calculus most CS students will take more pure mathematics courses like discrete and lin alg.

>I really loved math class before people felt the need to prove it works.
That's not math, that's just calculation.

see, this nigga get me

my mother died last year :'(

proof not rigorous enough

you forgot to take into account rigor mortis

You didn't post in a thread that said "...or your mother will die in her sleep"?

Trivial, the set of integers is a ring.

>i define that multiplication and summation of integers is a binary operation

>prove that multiplication of integers is integer
>prove that summation of integers is integer
these are equivalent due to multiplication being repeated addition.

now let N and M be natural numbers.
N + M = (1 + 1 + ... + 1) + (1 + 1 + ...+ 1), first bracket has N 1's second bracket M 1's. By the axiomatic construction (Peanos) of the natural numbers the summation is also a natural number as N + M.

QED.

FUCK OFF LAD.

ok lad, you proved it for naturals??

what if i 'proved' RH for numbers outside of the (0,1) strip??

You're a disgrace to physics majors. The spiritual equivalent of a code monkey.

>Just give me a formula to plug into hur dur

>I'm good at math because I can use formulas

>He thinks a naked set and a ring with elements in that set are the same thing