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Will the real TeeEm please stand up!

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Reply 960
Original post by SCAR H
TeeEm what Q were you referring to i think i complicated it? A or B


I was thinking of b

why does it matter now?
in 18 days you will get your results!
Reply 961
Original post by TeeEm
I was thinking of b

why does it matter now?
in 18 days you will get your results!


I know :smile: i respect you (obviously) but i just want to know why i wouldn't get the M1. Your replied was a little vague. Could you expand :smile:
Your work on your website is really helpful :smile:
Reply 962
Original post by SCAR H
I know :smile: i respect you (obviously) but i just want to know why i wouldn't get the M1. Your replied was a little vague. Could you expand :smile:
Your work on your website is really helpful :smile:


this is open to interpretation
a marker has some flexibility.

I could not possibly give any marks for something which is conceptually wrong, even if the correct solution is followed. (luckily I do not mark)

You might get 1 mark.
Reply 963
18 days to A level results

Question for Sunday 26/07/15
AS Level Maths Upwards


and for those who want that little bit extra,
Further Maths level Upwards required
(edited 8 years ago)
The normal one was interesting! I got a third for my solution is that anywhere near :colondollar:
Reply 965
Original post by Joshthemathmo
The normal one was interesting! I got a third for my solution is that anywhere near :colondollar:


the answer is indeed 1/3
Original post by TeeEm
18 days to A level results

Question for Sunday 26/07/15
AS Level Maths Upwards


and for those who want that little bit extra,
Further Maths level Upwards required


Just a minor typo in the extra, the sign in front of the π^8 should be a minus :smile:
Reply 967
Original post by Gome44
Just a minor typo in the extra, the sign in front of the π^8 should be a minus :smile:


thank you I will correct it.

I am uploading new questions and solutions early tonight
Reply 968
17 days to A level results

Question for Monday 27/07/15
AS Level Maths Upwards


and for those who want that little bit extra,
Further Maths level Upwards required
(edited 8 years ago)
Reply 969
16 days to A level results

Question for Tuesday 28/07/15
AS Level Maths Upwards


and for those who want that little bit extra,
A level Maths Upwards required
(edited 8 years ago)
Original post by TeeEm
16 days to A level results

Question for Tuesday 28/07/15
AS Level Maths Upwards


and for those who want that little bit extra,
A level Maths Upwards required


The second one is very very nice if you have to do what i think you have to.

Spoiler




Posted from TSR Mobile
Reply 971
Original post by physicsmaths
The second one is very very nice if you have to do what i think you have to.

Spoiler




Posted from TSR Mobile


solutions tomorrow...
today's problems are both easier than the usual questions

back to series and products soon
Original post by TeeEm
solutions tomorrow...
today's problems are both easier than the usual questions

back to series and products soon


Yh they look easy.


Posted from TSR Mobile
Original post by TeeEm
16 days to A level results

Question for Tuesday 28/07/15
AS Level Maths Upwards


and for those who want that little bit extra,
A level Maths Upwards required

Note square root of x^2 is mod x. I think you did x.
Ive done it a few times and i think your answer is wrong. Here is the solution. ImageUploadedByStudent Room1438060282.737025.jpg

Edit: just checked wolfram and gives me my answer aswell.
Posted from TSR Mobile
(edited 8 years ago)
Original post by TeeEm
solutions tomorrow...
today's problems are both easier than the usual questions

back to series and products soon


What do you reckon?


Posted from TSR Mobile
Reply 975
Original post by physicsmaths
What do you reckon?


Posted from TSR Mobile


sorry one of my classic typos?...
(edited 8 years ago)
Original post by TeeEm
sorry one of my classic typos...
It should read pi+4


I doubt that is right aswell.


Posted from TSR Mobile
Reply 977
Original post by physicsmaths
I doubt that is right aswell.


Posted from TSR Mobile


I am not in my office at the moment

why don,t you wait until tonight?
Original post by TeeEm
I am not in my office at the moment

why don,t you wait until tonight?


Sure No problem.
ImageUploadedByStudent Room1438083317.481544.jpg
Wolfram gives me the number of 1.81 or whatever which is equivalent to my answer in my solution above.
Would be nice if someone could check my answer to be sure its right.


Posted from TSR Mobile
(edited 8 years ago)
0π14sinx2+4sin2x2dx=0π(12sinx2)2dx=0π12sinx2dx\int_0^\pi \sqrt{1-4\sin \frac{x}{2} + 4 \sin^2 \frac{x}{2}} \,dx = \int_0^\pi \sqrt{(1-2\sin \frac{x}{2})^2}\,dx = \int_0^\pi | 1 - 2 \sin \frac{x}{2}| \,dx

1 - 2 sin (x/2) = 0 when x = pi/3, and is decreasing function (in range 0 < x/2 < pi/2) so > 0 for x < pi/3 and < 0 for x > pi/3.

So integral becomes

0π/312sinx2dx+π/3π2sinx21dx\int_0^{\pi/3} 1 - 2 \sin \frac{x}{2}\,dx + \int_{\pi/3}^\pi 2 \sin \frac{x}{2} - 1\, dx

=[x+4cosx2]0π/3[4cosx2x]π/3π =[x + 4 \cos \frac{x}{2}]_0^{\pi/3} - [4 \cos \frac{x}{2} - x]_{\pi/3}^\pi

=π32π3+8cosπ64=434π3 = \frac{\pi}{3} - \frac{2\pi}{3} + 8 \cos \frac{\pi}{6} - 4 = 4 \sqrt{3} - 4 - \frac{\pi}{3}
(edited 8 years ago)

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