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Has my tutor made mistakes in this answer?

Hi,
I'm a mature student studying for a maths A-level and am concerned my tutor may be making mistakes in what he is teaching me.

He was walking me through solving this inequality: |2x^2 - x| > 1.

He wrote there were two regions:

x<=0 where the function becomes 2x^2 + x > 1
and
x>=1/2 where it becomes 2x^2 - x > 1

but isn't the function:
2x^2 - x > 1 when x <=0 & x>= 1/2
and
x - 2x^2 > 1 when 0 < x < 1/2

His final answer was also x > 1/2 and x < -1 when I've got x < -1/2 and x > 1. Is he wrong here?
I'm wondering whether I should switch to a new tutor as I've noticed mistakes on several occasions before, which only served to confuse me.
Many thanks.

Scroll to see replies

Reply 1
Yes he's wrong.

It's not hard to check your answers (the boundaries) give 1 and his don't
Reply 2
Original post by RichE
Yes he's wrong.

It's not hard to check your answers (the boundaries) give 1 and his don't


Thanks, I just wanted to be sure. Does anyone have any thoughts on how much of a red flag these sort of mistakes are? I know everyone can make mistakes but it's not the first time it's happened and he charges above the going rate. Would you seek a new tutor?
Reply 3
Original post by neva30
Thanks, I just wanted to be sure. Does anyone have any thoughts on how much of a red flag these sort of mistakes are? I know everyone can make mistakes but it's not the first time it's happened and he charges above the going rate. Would you seek a new tutor?


I would consider this a straightforward A-level question. It depends a little on whether this was a question that the tutor did quickly on the spot in a rush - mistakes are then forgivable - or one they'd prepared - mistakes less forgivable.

But really I think this is a poor mistake to make, as a quick "sanity check" for one's answers is to put them back in the function - x=1 gives 1 and x = -1 doesn't so the tutor should have seen their mistake then.
(edited 6 years ago)
Reply 4
Original post by RichE
I would consider this a straightforward A-level question. It depends a little on whether this was a question that the tutor did quickly on the spot in a rush - mistakes are then forgivable - or one they'd prepared - mistakes less forgivable.

But really I think this is a poor mistake to make, as a quick "sanity check" for one's answers is to put them back in the function - x=1 gives 1 and x = 0 dpesn't so the tutor should have seen their mistake then.


Thanks for the reply, I'll have to give the matter some thought.
|2x^2 - x| > 1.

This is true if and only if 2x^x-x-1 > 0 or 2x^1-x+1<0.

The first inequality yields x<-0.5 or x>1. The second has no real values. Hence your answer is correct and he's wrong.
A tutor who offers A level tuition should definitely be able to provide a correct solution to this, without preparation.

I would look for another tutor if I were you.

May I ask what they are charging?
Reply 7
Original post by BuryMathsTutor
A tutor who offers A level tuition should definitely be able to provide a correct solution to this, without preparation.

I would look for another tutor if I were you.

May I ask what they are charging?


They're charging £66 per hour, which as far as I'm aware is a fair way above the standard rate.
Original post by neva30
They're charging £66 per hour, which as far as I'm aware is a fair way above the standard rate.


£66?!?!?! Holy damn. I charge £10 for online tuition for Maths and Further Maths. Making mistakes and earning that much - he's living the life.
Original post by neva30
They're charging £66 per hour, which as far as I'm aware is a fair way above the standard rate.


Might be time to put my rates up. :biggrin:
Original post by thekidwhogames
£66?!?!?! Holy damn. I charge £10 for online tuition for Maths and Further Maths. Making mistakes and earning that much - he's living the life.


Original post by BuryMathsTutor
Might be time to put my rates up. :biggrin:


Rates in the region of £60/h aren't as uncommon as you might expect. Particularly for those with a reputation that go to the client in the more affluent parts of London, for instance.
Original post by Farhan.Hanif93
Rates in the region of £60/h aren't as uncommon as you might expect. Particularly for those with a reputation that go to the client in the more affluent parts of London, for instance.


Yes true. But for A level Maths, something that can be self-taught due to the extensive amount of resources; coupled with the competition of other tutors, I would've not expected £66 xD
After reading initial comments, I though it would be best not to be too hasty and make such a rash decision, although granted such a mistake should never have been made.

Although after reading how much you are having to pay, 100% I believe you should be looking for another tutor, especially considering you mentioned mistakes have occurred on various occasions.

I know it's been mentioned that perhaps £60+ in certain areas isn't uncommon, but I still believe that's a comparatively extortionate price.
There should be many qualified tutors available that wouldn't make such careless mistakes and charge less of a premium for providing an arguably better service.

This is your money and your education, so it's your call.
Original post by Farhan.Hanif93
Rates in the region of £60/h aren't as uncommon as you might expect. Particularly for those with a reputation that go to the client in the more affluent parts of London, for instance.


Travelling to students and living in London that seems fair. I don't travel. I'd be charging close to that if I did.
Reply 14
Original post by BuryMathsTutor
Travelling to students and living in London that seems fair. I don't travel. I'd be charging close to that if I did.


Unfortunately this is an online tutor, no travelling involved. Having read everyone's comments I think I'll definitely switch, thanks everybody for your advice.
@BuryMathsTutor <- Mark tutors online. Just sayin' :mmm:

Good luck with your endeavour to find another tutor!
Continue to post on the forums if you ever need any help. We'll be more than happy to assist.
Original post by thekidwhogames
Yes true. But for A level Maths, something that can be self-taught due to the extensive amount of resources; coupled with the competition of other tutors, I would've not expected £66 xD


It depends on the attainment targets of the student, and how that lines up with their ability. If they're aiming for an A* and they've historically performed well but always fell short of an A, say, then it's hopefully clear why a tutor may be necessary and how self teaching will likely be insufficient on it's own.

Furthermore, it's a reputation-based industry and it's often a race against time (with exams closing in) - taking a gamble on a cheaper but unproven tutor is not something that many parents/students would like to do, particularly those that have the wealth associated with privately educating their children. Convenience vs cost is also a consideration that often ends up in favour of the former.

Original post by BuryMathsTutor
Travelling to students and living in London that seems fair. I don't travel. I'd be charging close to that if I did.


Absolutely, with your experience. All of my former clients have been around that mark.

Original post by neva30
Unfortunately this is an online tutor, no travelling involved. Having read everyone's comments I think I'll definitely switch, thanks everybody for your advice.


In light of that, 100%. If online is your preferred avenue, you can definitely top that! Best of luck with your search.
Original post by neva30
They're charging £66 per hour, which as far as I'm aware is a fair way above the standard rate.

66quids! In UAE, I paid like 30 quid an hours at max. Is your school private or public?
Original post by JaredzzC
@BuryMathsTutor <- Mark tutors online. Just sayin' :mmm:

Good luck with your endeavour to find another tutor!
Continue to post on the forums if you ever need any help. We'll be more than happy to assist.


I'm fully booked and writing a dissertation too so I'm not taking on any new students. 😕
Original post by Farhan.Hanif93
It depends on the attainment targets of the student, and how that lines up with their ability. If they're aiming for an A* and they've historically performed well but always fell short of an A, say, then it's hopefully clear why a tutor may be necessary and how self teaching will likely be insufficient on it's own.

Furthermore, it's a reputation-based industry and it's often a race against time (with exams closing in) - taking a gamble on a cheaper but unproven tutor is not something that many parents/students would like to do, particularly those that have the wealth associated with privately educating their children. Convenience vs cost is also a consideration that often ends up in favour of the former.



Absolutely, with your experience. All of my former clients have been around that mark.



In light of that, 100%. If online is your preferred avenue, you can definitely top that! Best of luck with your search.


Yeah that's true, I see where you're coming from.

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