You are Here: Home >< Maths

# Official TSR Mathematical Society Watch

1. (Original post by raheem94)
You are starting to grasp the concepts .

This is correct as well, i also get the same answer.
I know how to do them, I just didn't understand the wording..

I don't understand what they want for Q)15
2. (Original post by King-Panther)
I dont understand Q)15.

Do you know integration?
3. (Original post by raheem94)
Do you know integration?
Yeah

I got x^4-x-2

Also, what is d2y/dx2 of x^2+2+1/x^2
4. (Original post by King-Panther)
Yeah

I got x^4-x-2
So you got, , right?

But we need to add a constant of integration, c, because it is a indefinite integral.

So

Now use the conditions given in the question of y=17 and x=2 to find the value of 'c'.
5. (Original post by King-Panther)
Yeah

I got x^4-x-2
+c

Then sub in the numbers as given in the question.

6. (Original post by raheem94)
So you got, , right?

But we need to add a constant of integration, c, because it is a indefinite integral.

So

Now use the conditions given in the question of y=17 and x=2 to find the value of 'c'.
So 17=2^4-2^-2+c

Also, what is d2y/dx2 of x^2+2+1/x^2
7. (Original post by Zuzuzu)
+c

Then sub in the numbers as given in the question.

I did, but it was suggested this was the best place for me...
8. (Original post by King-Panther)
So 17=2^4-2^-2+c

Also, what is d2y/dx2 of x^2+2+1/x^2

Sub in y=17 and x=2 in the above expression, to find the 'c'.

So

You don't need to find d2y/dx2.
9. (Original post by raheem94)

Sub in y=17 and x=2 in the above expression, to find the 'c'.

So

You don't need to find d2y/dx2.
Also, what is d2y/dx2 of x^2+2+1/x^2

Also, how about Q)16, b? Do I treat it as a quadratic?

I really appreciate this!
10. (Original post by King-Panther)
I did, but it was suggested this was the best place for me...
11. (Original post by King-Panther)
Also, what is d2y/dx2 of x^2+2+1/x^2

Also, how about Q)16, b? Do I treat it as a quadratic?

I really appreciate this!
12. Can anyone help me?

http://www.thestudentroom.co.uk/show...1960422&page=7

http://www.thestudentroom.co.uk/show....php?t=1970327
14. Question: If you choose an answer to this question at random, what is the probability that you will be correct?
a. 25%
b. 50%
c. 0%
d. 25%

Question: If you choose an answer to this question at random, what is the probability that you will be correct?
a. 25%
b. 50%
c. 0%
d. 25%

e. mumble something vague about an ill-defined probability space and then regard the question with aloof disdain, claiming to have answered it fully and for it to be "trivial"

Spoiler:
Show
Or at least that's what Grimmett taught our year
Question: If you choose an answer to this question at random, what is the probability that you will be correct?
a. 25%
b. 50%
c. 0%
d. 25%

I'm guessing the law of the excluded middle features quite a bit in this paradox.

Logical bit
Spoiler:
Show

Assume a and d are correct. Then you have a 50% chance of answering the question right at random. SO a and d can't be right.

Assume b is right. Then you have a 25% chance of getting the questions right. So b is wrong

Assume c is right. Then you have a 0% chance iof getting the answer right so c is wrong.

Assume all the options are wrong, then you have a 0% chance of getting the answer right, so the answer is c. But then all the answers can't be wrong.

Philosophical bit
Spoiler:
Show

So both the answers "all answers are wrong" and "there is at least one correct answer" lead to contradictions. Thus the answer can be neither of them- unless we wish to change the meaning of truth to allow for (P ∧ ¬P) i.e. paradoxes or we accept that some statements are neither true nor false, i.e. we drop the law of the excluded middle: ¬(P ∧ ¬P).

I think this questions an example of one that can only be answered only with statements whose truth leads directly to a contradiction. Let's just say that such questions are undecidable and save a lot of time ;p

Another example of an undecidable question would be:
The sentence below is false
The sentence above is true
None of these three sentences are true.

Which sentences are true?

Nice problem though; a shame I had to ruin it with my logical analysis.: )
17. (Original post by Blutooth)
I'm guessing the law of the excluded middle features quite a bit in this paradox.
The law of excluded middle is . The formula you quote, , is tautological even in weak fragments of intuitionistic logic. It is just an internalised modus ponens: .
18. Alright fellow mathmos?!
19. GCSE stats coursework help please:
okay so i am doing coursework on track and field events in the Olympics i am focusing on the 2008 ones but i don't know if you can create a cumulative frequency diagram with the data that i have i have decathlon and individual data both with the events of 100m sprint and high jump help please its in for next week and i have no idea what i am doing please help!?!
20. [*] During the weekends, Eli delivers milk in the complex plane.

On Saturday, he begins at and delivers milk to houses located at , in that order.
On Sunday, he begins at and delivers milk to houses located at , in that order.

Eli always walks directly (in a straight line) between two houses.

If the distance he must travel from his starting point to the last house is on both days, find the real part of .

Updated: August 3, 2015
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

You still have time to swap.

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams