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Edexcel Maths higher boundaries A*-A

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Original post by M4keen04
the question asks you to work out AREA. Remember, pythagoras is for length of a side. the info given already gives you all the lengths that you need,as you dont need the length of the hypotenuse side.


To find out what the area is, it is base x height x 0.5. To work that out, the question has given us the base and height of the big triangle, and the HYPOTENUSE of that big triangle is the BASE of the small triangle. And to find out what the height was, you had to rationalise the denominator. I think I got the answer wrong in the end. But finding out the base of the small triangle gives me at least 1 mark
Original post by Faizanasif
To find out what the area is, it is base x height x 0.5. To work that out, the question has given us the base and height of the big triangle, and the HYPOTENUSE of that big triangle is the BASE of the small triangle. And to find out what the height was, you had to rationalise the denominator. I think I got the answer wrong in the end. But finding out the base of the small triangle gives me at least 1 mark


No, yuore thinking of it a different way. youre thinking of the the shaded region as the small traingle. the small traingle which you use to find out the area of the shaded region is traingle ABD or whatever, therefore, you dont need to work out the length of that hypotenuse, so that wouldnt be any marks. for the shaded region which you think of as the small traingle, it is not a right angled triangle, so u cant use basex height x 0.5. youd need 0.5absinC, which u cant do (non calc), so your method wont work.

also, the lenghts are rationalised, as the denominators were whole numbers, while the numerators were surds.
Original post by M4keen04
No, yuore thinking of it a different way. youre thinking of the the shaded region as the small traingle. the small traingle which you use to find out the area of the shaded region is traingle ABD or whatever, therefore, you dont need to work out the length of that hypotenuse, so that wouldnt be any marks. for the shaded region which you think of as the small traingle, it is not a right angled triangle, so u cant use basex height x 0.5. youd need 0.5absinC, which u cant do (non calc), so your method wont work.

also, the lenghts are rationalised, as the denominators were whole numbers, while the numerators were surds.


I swear it was something like 2/root 3 and 3/root 2, so surely rationalising is the method.

Anyway, like I said before, that's the only question I couldn't be confident to answer. The rest of the paper was brilliant. Lucky that this was only the 3 marks lost, and Circle Theorems and Vectors which I love were something like 15 marks together

At the end of the exam, I didn't approach 2 people who said the same answer as them, so most people would get that wrong, hence the grade boundaries will lower due to this
Original post by Faizanasif
I swear it was something like 2/root 3 and 3/root 2, so surely rationalising is the method.

Anyway, like I said before, that's the only question I couldn't be confident to answer. The rest of the paper was brilliant. Lucky that this was only the 3 marks lost, and Circle Theorems and Vectors which I love were something like 15 marks together

At the end of the exam, I didn't approach 2 people who said the same answer as them, so most people would get that wrong, hence the grade boundaries will lower due to this


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Original post by M4keen04
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Wait, I remember my teacher saying it is ok to have an irrational number at the numerator as well
Original post by M4keen04
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By the way, when I was saying to use Pythagoras to work out the base of the smaller triangle, that is right! So I have got 1 mark at least!
Original post by Faizanasif
Wait, I remember my teacher saying it is ok to have an irrational number at the numerator as well


an surd number at numerator is not an irrational fraction
Original post by Faizanasif
By the way, when I was saying to use Pythagoras to work out the base of the smaller triangle, that is right! So I have got 1 mark at least!


no, what would that achieve? how would that help you work out the area?
Original post by Faizanasif
By the way, when I was saying to use Pythagoras to work out the base of the smaller triangle, that is right! So I have got 1 mark at least!


...I don't think so. I'd assume the mark scheme is like this:

Working out of the whole triangle ABD's area M1 (1 mark)
Working out triangle ADC's area M1 (1 mark)
Subtracting the two areas to find the triangle ABC's area A1 (1 mark)
Original post by CloakedSpartan
...I don't think so. I'd assume the mark scheme is like this:

Working out of the whole triangle ABD's area M1 (1 mark)
Working out triangle ADC's area M1 (1 mark)
Subtracting the two areas to find the triangle ABC's area A1 (1 mark)


Ah, I see what you've done now. But seeing I've worked out using Pythagoras shows that there's another method of doing this. So you've done the less complex one. They'll be another method saying 1 mark for Pythagoras, 1 mark to work out the height then 1 mark for calculating area
Original post by CloakedSpartan
...I don't think so. I'd assume the mark scheme is like this:

Working out of the whole triangle ABD's area M1 (1 mark)
Working out triangle ADC's area M1 (1 mark)
Subtracting the two areas to find the triangle ABC's area A1 (1 mark)


finally, someone who understands what im trying to explain!
Original post by M4keen04
no, what would that achieve? how would that help you work out the area?


Because I remember it saying AD is this, so you can subtract the height of the big triangle from that to work out the height. But you needed to rationalise to do that, so I did that. I may have got the ending of it wrong, which is why I'm saying I should get 1 mark for it
Original post by Faizanasif
Ah, I see what you've done now. But seeing I've worked out using Pythagoras shows that there's another method of doing this. So you've done the less complex one. They'll be another method saying 1 mark for Pythagoras, 1 mark to work out the height then 1 mark for calculating area


What equation did you use for figuring out the smaller triangle's area though? Can't use 1/2 x side1 x side2 as it's not right-angled, can't use 1/2absinC as it's non-calculator.
Original post by CloakedSpartan
What equation did you use for figuring out the smaller triangle's area though? Can't use 1/2 x side1 x side2 as it's not right-angled, can't use 1/2absinC as it's non-calculator.


Yeah that's where I got wrong. I didn't notice it was a right angle triangle which is why I got the wrong answer in the end. But what I'm trying to tell you is that I worked out the hypotenuse of the big triangle, so that is 1 mark. I'm not saying I got it right!
Original post by Faizanasif
Yeah that's where I got wrong. I didn't notice it was a right angle triangle which is why I got the wrong answer in the end. But what I'm trying to tell you is that I worked out the hypotenuse of the big triangle, so that is 1 mark. I'm not saying I got it right!


Yeah but that's the thing, there's nothing you could've done by working out the hypotenuse as the method is invalid - there's no way to work out the area using the hypotenuse in a non-calculator paper, perhaps in a calc you could.
Original post by CloakedSpartan
What equation did you use for figuring out the smaller triangle's area though? Can't use 1/2 x side1 x side2 as it's not right-angled, can't use 1/2absinC as it's non-calculator.


exactly, as i explained before, therefore no marks for pythagoras
(edited 7 years ago)
Original post by CloakedSpartan
Yeah but that's the thing, there's nothing you could've done by working out the hypotenuse as the method is invalid - there's no way to work out the area using the hypotenuse in a non-calculator paper, perhaps in a calc you could.


Yeah I see what you mean now, sorry guys!

I'm quite weak on non calculator, but I'm much stronger on calculator (I got 97 on the calculator and 89 on the non calculator in the trial exam in March). Hopefully I'll be in form for the next one!
I've lost 30 marks in Paper 1, is it still possible to get an A*?
Original post by Adzkii786
I've lost 30 marks in Paper 1, is it still possible to get an A*?


You'll need at least 90 to get an A*. Most likely around 92-93, but try and aim for 95, as it can go up to 95, but that would be the absolute highest
Reply 99
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emabibi
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Original post by Faizanasif
An A* for this exam would most likely be around 161-163, depending on the calculator paper

Some found the exam really difficult, but I thought it was fine! Maybe I was over prepared :biggrin:




What do you think you would need out of 200 to get a B in maths. What the lowest and what's the highest?
Thank you

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