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Original post by King-Panther
The next question, I got dy/dx = 12x + 5

So when gradient is 13, I did

13 = 12x + 5

which is x = 2/3


You are starting to grasp the concepts :wink:.

This is correct as well, i also get the same answer.
Original post by raheem94
You are starting to grasp the concepts :wink:.

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
Original post by King-Panther

I dont understand Q)15.



Do you know integration?
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
(edited 11 years ago)
Original post by King-Panther
Yeah

I got x^4-x-2


So you got, x4x2 \displaystyle x^4 - x^{-2} , right?

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

So y=x4x2+c \displaystyle y= x^4 - x^{-2} + c

Now use the conditions given in the question of y=17 and x=2 to find the value of 'c'.
Reply 3665
Original post by King-Panther
Yeah

I got x^4-x-2


+c

Then sub in the numbers as given in the question.

You're probably best off creating your own thread for these questions.
Original post by raheem94
So you got, x4x2 \displaystyle x^4 - x^{-2} , right?

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

So y=x4x2+c \displaystyle y= x^4 - x^{-2} + c

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
(edited 11 years ago)
Original post by Zuzuzu
+c

Then sub in the numbers as given in the question.

You're probably best off creating your own thread for these questions.


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

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


y=x4x2+c \displaystyle y= x^4 - x^{-2} + c

Sub in y=17 and x=2 in the above expression, to find the 'c'.
17=2422+c    17=1614+c    c=54 17 = 2^4 - 2^{-2} + c \implies 17=16- \frac14+c \implies c=\frac54

So y=x4x2+54 \displaystyle y=x^4-x^{-2}+\frac54

You don't need to find d2y/dx2.
Original post by raheem94
y=x4x2+c \displaystyle y= x^4 - x^{-2} + c

Sub in y=17 and x=2 in the above expression, to find the 'c'.
17=2422+c    17=1614+c    c=54 17 = 2^4 - 2^{-2} + c \implies 17=16- \frac14+c \implies c=\frac54

So y=x4x2+54 \displaystyle y=x^4-x^{-2}+\frac54

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!
Original post by King-Panther
I did, but it was suggested this was the best place for me...


Its better you use your previous thread, 'integration', or make a new thread don't post in this thread.
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!


Treat 16b as a quadratic. And please don't post in this thread, use your previous thread again or make a new thread.
(edited 11 years ago)
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%

:smile:
Reply 3675
Original post by Dadeyemi
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%

:smile:


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

Original post by Dadeyemi
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%

:smile:


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

Logical bit

Spoiler



Philosophical bit

Spoiler



Nice problem though; a shame I had to ruin it with my logical analysis.: )
(edited 11 years ago)
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 p¬pp \lor \lnot p. The formula you quote, ¬(p¬p)\lnot (p \land \lnot p), is tautological even in weak fragments of intuitionistic logic. It is just an internalised modus ponens: (p(p))(p \land (p \to \bot)) \to \bot.
Alright fellow mathmos?!
GCSE stats coursework help please: :s-smilie:
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!?!

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