Exploring Interesting Plant Facts

[e^(i Pi)+1=0]

?

 

[Dadface]

Why do you think your teacher gave "points off"?

 

[Mentallic]

You need to be more specific. What was the question?

Maybe you were restricted to the values of $-\pi/2$ to $\pi/2$ for example.

 

[e^(i Pi)+1=0]

I guess I should have given more information. It was a no-calculator test. The part I'm talking about you had to fill in the famous unit circle chart.

 

[HallsofIvy]

Then perhaps you were expected to say $tan(\pi)= tan(2\pi)= 0$ rather than using degrees.

 

[e^(i Pi)+1=0]

 

[Mark44]

Your instructor probably dinged you for writing ∅ (empty set) instead of 0. He or she might have been confused because you write ∅ in some places and 0 in others, without consistency.

 

[HallsofIvy]

However, he/she did not take points off for that same answer for $\theta= 0$. I'm confused!

 

[Dadface]

However, he/she did not take points off for that same answer for $\theta= 0$. I'm confused!

Could be speed marking and the teacher overlooked it.Having had another look it seems as if he/she deducted four marks(-1 and -3)

 

[e^(i Pi)+1=0]

No, it was only -1. There was also a -2 higher up on the page.

 

[Mentallic]

Why don't you ask her why she removed the marks?

 

[e^(i Pi)+1=0]

Oh I plan to...

 

[jey1234]

I'm pretty sure it's what Mark44 said and she probably won't change her mind but it's always worth asking

 

[Mentallic]

Your instructor probably dinged you for writing ∅ (empty set) instead of 0. He or she might have been confused because you write ∅ in some places and 0 in others, without consistency.

I doubt that's the case, because for one, she wasn't consistent in dragging down marks for each time he wrote the empty set, also, it's sometimes common practice to write zero with the slanted line through it to denote that it is in fact zero as opposed to the letter O. And finally, if he's answering simple trig questions, I doubt they've learned about sets yet.

 

[NascentOxygen]

I think I, too, would have deducted marks, as it appears you changed a 1 to a 0, or a 0 to a 1, and it's not clear what your final answer is supposed to be. Or else you are hedging your bets and hoping to be given the benefit of the doubt whatever the correct answer may be. :tongue:

 

[e^(i Pi)+1=0]

What are you talking about? Where did I change a one to a zero?

 

[Borek]

You crossed zero can be interpreted as you changed 1 to 0 (or vice versa). Doesn't mean you did, but it is not necessarily obvious you didn't.

 

[Ray Vickson]

What are you talking about? Where did I change a one to a zero?

Nobody said you did; they just said it looked like you might have, and that is probably why marks were taken off. (A 0 with a line through it *might* be interpreted as a zero crossed out, rather than a zero.)

RGV

 

[micromass]

Why did you write 0 in some place and $\emptyset$ in other places??

 

[e^(i Pi)+1=0]

Why did you write 0 in some place and $\emptyset$ in other places??

No reason. I always put a slash through my zeros but just forgot here for some reason.

 

[scurty]

No reason. I always put a slash through my zeros but just forgot here for some reason.

That's probably a habit you should try to break. Even as early as Calculus the null set it used, it will just cause confusion.

The earliest time in my math career that I could remember using the letter O to denote something was in Topology to denote open sets. It's a pretty safe bet you won't be confusing Os with 0s. I'd say the only necessary "strike through a symbol" you need to do is for zs to not confuse them with 2s.

 

[tiny-tim]

No reason. I always put a slash through my zeros …

don't

stop it!

you must use the same notation as the rest of your community

well worth losing 1 point to correct this ​

 

[Curious3141]

I think you should argue your case. It is a recognised alternative notation, even though you used it somewhat inconsistently here. You don't deserve to have those marks subtracted away for having a concept that's right, and having represented that concept on paper in a reasonably acceptable fashion. In your place, I'd fight for the marks, especially if they mattered.

The "cancellation" interpretation doesn't hold water, because a cancellation should be accompanied by a correction (replacement text). Obviously, that's not the case here.

To those arguing that he should be adhering to strict popular conventions, well, what about in other cases, for e.g. when a student write a '7' with a line through the middle (as I do)? In some places, that's common; whereas in others, it isn't. Should a student calmly accept it if a teacher marks him wrong for that?

There's no question of confusion with the 'empty set' notation in this instance, either.

 

[Mentallic]

I agree with Curious, but I should stress that you'll probably be better off not pushing the subject about those marks if they don't mean anything significant. Just mention it to your teacher so both you and him/her can be aware of what happened and of what could be changed for future reference.

Don't come off as someone that tries to force as many changes after marking out as possible, because I've seen other fellow students do that and it doesn't bode well for them in the end. It'll make your case stronger if you do think you deserve marks later on in tests that matter.

 

[tiny-tim]

o those arguing that he should be adhering to strict popular conventions, well, what about in other cases, for e.g. when a student write a '7' with a line through the middle (as I do)? In some places, that's common; whereas in others, it isn't.

but a '7' with a line through the middle is still a number

an 'O' with a line through it (protruding on either side) is something else

 

[NascentOxygen]

you must use the same notation as the rest of your community

When I learned FORTRAN, the textbook samples had a slash through the zero to distinguish zero from Capital O. Then in another subject (I think it was APL) the code had the slash through the Capital O to distinguish it from zero https://www.physicsforums.com/images/icons/icon4.gif

I have on more than a few occasions mistaken a student's handwritten 7 with a slash through it as a lower case "t" in a formula involving t for time---some give their t's serifs.

well worth losing 1 point to correct this ​

+2

 

[e^(i Pi)+1=0]

Boy this thread has gotten a lot bigger than I anticipated...

 

[Mentallic]

Because it's more of a thread based on one's opinion as opposed to homework help, and there sure are a lot of different opinions going around

 

[jing2178]

Perhaps the teacher thought that the zero with a line through it was an attempt at writing a theta (OK it looks more like phi but let's say the teacher was being generous with the writing of Greek letters) in which case as in the first column the value of theta is zero and so writing theta as the answer for sin(theta) and tan(theta) is correct as when theta=0 sin(theta)=tan(theta)=theta. This would not be true in later columns.

 

[Borek]

Basically what you wrote is ambiguous and can be understood in many possible ways. Math doesn't like ambiguous answers.

 

[RufusDawes]

b.c ppl draw 1s on a 45 degree angle now ?