Mathematics classwork graded incorrectly?
Hello everyone,
I got an important test back today that asked for the solution of the square root of -100.
I knew that the result would not be a real number, so I wrote ∈ R with a line through it to indicate that the number is imaginary.
She probably wanted it to say "not solvable."
This has now been marked as wrong, now the question:
Is that okay? Mathematically, it's correct, but can she mark it as incorrect?
Thanks in advance!
(1 votes)
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After my interpretation of the word “determine” one should have given a specific numerical value here. The equality sign also points to this.
Your answer is basically not wrong, but it does not solve the task. Therefore, the “f”, which in this context should probably only signal that your answer does not receive points.
EDIT (after attentive reading of your text): So obviously you haven’t dealt with any complex figures yet. It would have been the right thing to do. I’d go to the teacher and stick to the point.
Hey, thanks for the answer.
In class work, only real numbers were counted, with other pupils the answer was “?” and “/” as correct.
The combination of the equality sign and directly afterwards ∉ is mathematically not correct, but this is really very petty and pricky by your teacher.
The statement is true in terms of content, but not every correct statement is also the answer to the question or question. Task.
Were there any indication in what number space should be expected?
If it weren’t for me the solution was 10i – vl. that was asked.
Hey, thanks for the answer.
In class work, only real numbers were counted, with other pupils the answer was “?” and “/” as correct.
Then I’d be looking for the conversation with the teacher. Because a “?” or “/” is definitely not more correct than what you wrote. Isn’t she clear – depends on your note? If not, take off. If I did, I would first address another teacher, for example the specialist (the upper teacher, as always the one in the federal state) or something.
It is very annoying that teachers exert their power through such pea census
Can she?
If certain formulations are prescribed, then others are marked as wrong
Thanks for the answer.
However, I must say that before work there was no indication of how such tasks are to be solved, he told DANACH that one should write “not detachable”.
So if it allows “non-detachable” behind the equality mark at the place, it must also allow your indication, even if it looks somewhat different than usual:
However, both would be syntactically wrong, because behind a parable no further operator would be expected and a text would not be more likely.
One more note: Correct would have been an empty quantity (more precisely an empty quantity over scalar). A root can have two solutions, insofar it is the result of root operation a lot. If a root operation has no solution, this amount would be empty.
Outstanding objection!
Your answer is perfectly correct – but this is probably more about education than thinking…
Would root from -100 not be more element of complex numbers (i.e. C)?
Yes, the number is purely imaginary, so not element of real numbers, as the questioner answered correctly…