Doing math test

>Doing math test
>Correctly answer an integral
>Professor marks me off because it was dTheta and I wrote everything in terms of dx

The professor is actually, and literally right to do this in this type of a situation, and you are actually wrong.*

Seeing and phrasing everything in terms of x, to the point of not thinking about the symbol you use, is a secondary-school way of thinking, which it's time to start growing out of once calculus comes around - whether that happens in HS or in college. Not because the symbols matter, but because it becomes necessary to use more than one or two symbols to represent various unknown quantities, parameters, etc. You are literally wrong.

Here is your exercise set: learn the greek alphabet, cold.

*If you did everything right except for your notational mistake then the prof should /probably/, but not necessarily give you partial credit. But you literally do not deserve full credit if you missed this detail. Learn to use other symbols apart from x.

this is very advanced autism. variable names do not change the truth value of a logical argument.

No but when you use x for your domain and x for your range, things can get very confusing fast; just because you can does not mean you should

I had no impression that OP was doing so

They absolutely do, if they are being confused in the course of phrasing whatever is being discussed.

It's not even /full pedantry/. That's what both you and the OP don't understand. It actually goes to substance, downstream. A certain attention to detail, and yes, bookkeeping, is absolutely necessary to a properly phrased mathematical argument - /in order to preserve the substance of what is being expressed/. That said, it should be straightforward for a grader to see where the OP was going, and so in my view this should warrant partial credit ---

But not full credit. Before long, you'll be grading linear algebra exams where several distinct items are denoted as "x". See where I'm going with this?

I'm ashamed on your behalf that you don't seem to be the same person as the OP, as evidenced by the poster-count as of the time of your post (3: you, me, the OP)

>But not full credit. Before long, you'll be grading linear algebra exams where several distinct items are denoted as "x". See where I'm going with this?

it is full pedantry at this point. the difference between several distinct items denoted x and a single integration variable denoted x should be obvious to a grader.

The other poster is basically making the same point that I've been harping on, that one must become comfortable with employing multiple, distinct symbols to express various things in beginning to learn what I call "intermediate" (undergrad-tier) math. If you don't get docked points on a test for not paying attention, how else are you going to get the message?

yes you are quite harping on details that some people might not feel important to their work. not every single student is going to be a mathematical researcher and so not every single single student needs to be able to communicate in the narrow fashion the instructor or grader prescribes.

Fuck off its a math problem not your engineering homework

>let theta be an element of a set
>uses x

looks like you didn't make the dedekind cut

No, it isn't, because your argument assumes that it's the grader's job to divine intention at all times, and to demonstrate knowledge of intent (to the student, by granting full credit, say?) based on such-and-such writing. But it's the other way round: the /student's/ job is to demonstrate proficiency to the grader. This necessarily involves a certain standard of attention to detail and bookkeeping, along with the rest of it. That said, of course a grader will see what a student /meant/, or /thought he meant/, but this is where I'm right: if you want to do other math-y things, you have to get out of HS brainlet only-x mode, to put things concretely.

Your argument is exactly backwards.

It's interesting to me that you've projected "my engineering homework" onto that post. In truth, attention to detail is required in both disciplines, so your rhetorical fails any way you might try to push it.

there is no difference between a theta and an x and if x appears in a problem as an integration variable. are you legitimately confused when I write int(sin(x)) from 0 to pi? for all we know this is calc 2. for all we know he doesn't understand coordinate transformations yet. your argument assumes the student knows what we assume the student knows which is obviously impossible. stop doing the // thing it /is fucking irritating/

That's the point though, I know that no professor would care about x or theta in math problem but in a science the symbols do matter

Inconsistencies in variable names do tho

100% yes

Mind your variables, been there as well.

finally some got-damn sanity. What I get for talking to teenagers.

reminder you're still the guy that get's triggered when I don't pick a single letter from the alphabet of your choosing

Assuming you're the OP or any sympathizers he may have had, the real proof is in the OP's initial complaint. Which is that the grader was right to dock (you?) points, and that /you/ were triggered enough to make this thread in the first place.

If you are the OP and you persist in your buttmad, then you really have learned nothing. It goes to the foolishness of this comment, where "in sciences the symbols do matter" yet in "math they don't matter (somehow!). Teenagers.

I graded a bunch of exams just like this tonight. I took off points every time for the mistake you made. The differential matters, it's an object in of itself, not a placeholder. Changing the symbol of the variable in the differential without changing the symbol in the integrand produces an entirely different result. If you think your intention matters in mathematics, you're entirely wrong. Mathematics doesn't care what you meant to do, it only works if you do things precisely. If you don't understand why you got points deducted, then you're like a child getting the number 2 confused with the number 5 and expecting people to understand which one you meant.

more weight. Very well said.

> Changing the symbol of the variable in the differential without changing the symbol in the integrand produces an entirely different result.

It... yeah no shit. But there's no indication that the OP did that. It sounds like they just wrote:

$$\int_a^bf(x)dx$$

rather than

$$\int_a^bf(\theta)d\theta$$

You're acting as if they wrote

$$\int_a^bf(\theta)dx$$

>If you don't understand why you got points deducted, then you're like a child getting the number 2 confused with the number 5 and expecting people to understand which one you meant.
Amazing analogy user

You just outed yourself as a brainlet who doesn't actually think when solving these problems and instead just goes through the motions of pattern matching from your 'studying' of integrals.

It's unlikely you wouldn't been deducted more than half a mark or anything significant depending on how each problem is weighted (assuming your brainlet ass actually solved the problem correctly despite using the incorrect symbol).

Get over it and don't do it again.

If he changed the names of the variables that would suggest that he has insight that many don't that the name of the variable doesn't matter. I can't imagine a single situation where renaming a variable should warrant any deduction, unless specifically told not to, and then it would be deduction to teach people to follow instructions.

Should have written "let x=theta" at the beginning cuck

Absolute brainlet.

>he doesn't speak greek

why do you brainlets even try

>integrating something wrt x
>now chooses to integrate wrt theta
>all x terms now treated like constant and you get a theta term
idiot

Your fault really, you would at least have had to produce a proof of how [math]\mathbb R[x]\cong \mathbb R[\theta][/math] then isomorph your result into the [math]\theta[/math] space

Absolutely and one hundred percent wrong.

Happily, as the thread has progressed, other non-children have slowly emerged, like this one - though they took their sweet time.

le smart and lazy hahaha :DDDDDD

Dont be a fucking dipshit and apply some precision to your work, it doesnt only show your ability to write correctly but also that you actually thought about what you put on the page. This is literally elementary school level shit of show your work. If I was your TA I would roast you in a tutorial with this as an example to hammer the point.

You deserve it. The professor knows there are student who for some reason think "x" is a magical object, not only a letter. Students who if you give them a problem in terms of y they will think y is a function, not a variable and do some retarded shit.

OP, you are stupid. You clearly do not understand calculus.

This is pretty much right. The professor ought to give most of the credit for that problem at least. Although, I would add that switching symbols is fine on tests as long as you add a line declaring the original symbol and your new one to be equal.

When I was taking all the math prereqs for declaring math at my uni, I often redefined variables for either ease of writing or just to amuse myself. Technically, the logic all checks out as long as you declare the new symbol to be equivalent to the old.