I believe for today's exam we all have the shared acknowledgement that it is difficult, however given the solution and explanations, but for instances on the question used the notation [a, b] and very little used ]a, b[ instead of the more commonly used (a, b) , without explicit explanation on the notation, and also after consulting the TAs during the exam I was told that they "cannot tell me whether it is a typo"... If being told what.
I feel that the exam in a way could be made clearer and easier if used more common terminologies, and I think it would be very nice if such point can be taken into account when grading...
Same here, also first time saw such notation of ] [ instead of (). Thought it is a typo, so marked arccos function as the correct answer along with f1 and f4 :(
Checked that for similar questions in 2017 and 2016 exams were notation with () and []. So that's even more strange that it was changed. Wish the answer may be still counted as the correct one.
whats even more absurd is that some authors use \(]a,b[\) to denote the complement of \( (a,b) \), so in this interpretation \(f_3\) attains a global maximum on \(x=1\)
I completely agree! I made an error on that question just because of the notation (I thought it was a typo). All around the world (except for France) \((a, b)\) is being used. Furthermore, I do not remember seeing such a notation in any of the course materials.
we're aware of this issue. once we have graded everyone's answer on this, we'll see if people were confused, and if necessary will count both interpretations as correct. first we need to do all grading though
Just to add another interpretation, I had also never seen ][ notation and I interpreted it by saying things outside the set were valid. As in I thought [0,1] means between 0 and 1 inclusive; so ]0,1[ means outside of 0,1 inclusive, i.e. [-inf,0) union (1,inf].
@martin said:
we will count both answers as correct here (so it is full points both if you did include arccos or not)
this question is just weird, then. this way you’re accepting that ]a,b[ is a typo. but as discussed earlier it can be thought of (not misread, it’s introduced in the literature) as the complement of [a,b], in which case the function f3 also attains a maximum.
@martin said:
we will count both answers as correct here (so it is full points both if you did include arccos or not)
this question is just weird, then. this way you’re accepting that ]a,b[ is a typo. but as discussed earlier it can be thought of (not misread, it’s introduced in the literature) as the complement of [a,b], in which case the function f3 also attains a maximum.
Comments regarding notation in the exam (Q6)
I believe for today's exam we all have the shared acknowledgement that it is difficult, however given the solution and explanations, but for instances on the question used the notation [a, b] and very little used ]a, b[ instead of the more commonly used (a, b) , without explicit explanation on the notation, and also after consulting the TAs during the exam I was told that they "cannot tell me whether it is a typo"... If being told what.
I feel that the exam in a way could be made clearer and easier if used more common terminologies, and I think it would be very nice if such point can be taken into account when grading...
8
I agree with that... I thought it's a typo...... but it is not
6
Same here, also first time saw such notation of ] [ instead of (). Thought it is a typo, so marked arccos function as the correct answer along with f1 and f4 :(
6
I agree, the exam was super hard!
I mean many of the questions were really tricky!
I hope they really consider this during grading!
2
Checked that for similar questions in 2017 and 2016 exams were notation with () and []. So that's even more strange that it was changed. Wish the answer may be still counted as the correct one.
5
No way. I had the same thought as you guys. Never seen this one before
In France we use it a lot
2
not everyone from France
4
whats even more absurd is that some authors use \(]a,b[\) to denote the complement of \( (a,b) \), so in this interpretation \(f_3\) attains a global maximum on \(x=1\)
5
I completely agree! I made an error on that question just because of the notation (I thought it was a typo). All around the world (except for France) \((a, b)\) is being used. Furthermore, I do not remember seeing such a notation in any of the course materials.
1
we're aware of this issue. once we have graded everyone's answer on this, we'll see if people were confused, and if necessary will count both interpretations as correct. first we need to do all grading though
6
Just to add another interpretation, I had also never seen ][ notation and I interpreted it by saying things outside the set were valid. As in I thought [0,1] means between 0 and 1 inclusive; so ]0,1[ means outside of 0,1 inclusive, i.e. [-inf,0) union (1,inf].
we will count both answers as correct here (so it is full points both if you did include arccos or not)
2
this question is just weird, then. this way you’re accepting that ]a,b[ is a typo. but as discussed earlier it can be thought of (not misread, it’s introduced in the literature) as the complement of [a,b], in which case the function f3 also attains a maximum.
5
I have the same thought
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