Mathematics: Post your doubts here!

[Bilal Khan]

Use sin3theta = 0.75 to calculate values of theta.
theta = 0.283
theta = 0.765
Now you have to use the equation given earlier. X = 2sin(theta)/sqrt3 with these 2 values of theta to get the first 2 solutions.
Further positive values of theta won't work because if you make a table of the function, you'll see that it keeps increasing after 0.8. So the third solution is for a negative value of theta.
theta = -1.329 and put this in X = 2sin(theta)/sqrt3 to get the last answer.

Can you show it by doing , like sending a pic.

 

[sara kamal]

ii) split into 2 cases
1. Thousand digit is 3
1st digit: 1 choice (can only be 3)
4th digit: 2 choices ( can only be 4 or 8)
2nd digit: 5 choices(any of the remaining)
3rd digit: 4 choices(any of the remaining)
2. Thousand digit is 4
1st digit: 1 choice (only 4)
4th digit 1 choice (only 8)
2nd digit: 5 choices
3rd digit: 4 choices
Total = (2*5*4) + (5*4)

iii) Split into 3 cases:
1. 1 digit number: 1 choice (5 only)

2. 2 digit number:
2nd digit: 1 choice ( 5 only)
1st digit: 7 choices

3. 3 digit number
3rd digit: 1 choice
1st and 2nd digit: 7 choices each
Total = 1 + 7 + (7*7)

thanks alot!

 

[sara kamal]

(ii) All numbers must start with either 3 or 4 to be between 3000 and 5000 and end with 4 or 8 to be even numbers.
They can be like 3__4, 3__8 or 4__8. Cannot be 4__4 as digits aren't repeated.
Total available digits are 7 so remaining for the middle two digits are 5. There are 2 spaces so 5P2. This will be thrice as there are 3 combinations for first and last digits. Hence total numbers that can be made are 5P2*3=60.

(iii) Numbers can be 1-digit, 2-digit and 3-digit. All numbers must have 5 as last digit to be a multiple of 5 as 0 is not available. So there will be 1 1-digit number. 7 2-digit numbers as first digit of these numbers can be any one of the seven available digits as digits can be repeated so they will be 35, 45 etc. There will be 49 3-digit numbers as both first and second digits can be any of the seven available digits. These will be 485, 145 etc. Total are 1+7+49=57.

thanks alot!

 

[ahmedish]

hey does anyone know any tips for the actual exam? like how to check your answers to make sure youre going in the right direction and such?

 

[ahmedish]

Someone help me with this S1 problem. It's from O/N/13 - 61. I solved it (attached the picture) - my distribution for X is wrong; can someone please explain why the distribution for X is lower than that for Y? I attached the markscheme screenshot too, haha. Please help!
View attachment 52744
View attachment 52746

youre 3 standard deviations below and above the mean. so 3 x sqr rt of 49 below and above, so 21 below 30 and 21 above 30 and so from 9 to 51

 

[Heyyy]

hey does anyone know any tips for the actual exam? like how to check your answers to make sure youre going in the right direction and such?

Are you asking about P3 or S1?
In P3 it is better just to review your answer and then proceed to the next.If you start checking whether your answer is correct it will take a lot of time and cause trouble later.Just review the working for any careless errors.In the end if you have time go through all the answers again,especially those you have your doubts on.In p3 it will be better to solve the easier questions first;those you're well acquainted with.

In S1,leave permutation and combination for the last.You should attempt other questions in order.I don't think there is any way to check your answers except for in normal distribution where you can check the probability by reversing.Again,it would be helpful to check in the end if time permits.

Try not to confuse yourself about a particular solution.There are times when you think what you've done is wrong although it's correct.

 

[Emadthegreat]

Are you asking about P3 or S1?
In P3 it is better just to review your answer and then proceed to the next.If you start checking whether your answer is correct it will take a lot of time and cause trouble later.Just review the working for any careless errors.In the end if you have time go through all the answers again,especially those you have your doubts on.In p3 it will be better to solve the easier questions first;those you're well acquainted with.

In S1,leave permutation and combination for the last.You should attempt other questions in order.I don't think there is any way to check your answers except for in normal distribution where you can check the probability by reversing.Again,it would be helpful to check in the end if time permits.

Try not to confuse yourself about a particular solution.There are times when you think what you've done is wrong although it's correct.

what abt s2?

 

[Heyyy]

what abt s2?

I don't take s2.

 

[asadalam]

I don't take s2.

Any help in permutations?I never seem to get those ones right,even if all else is correct.

 

[The Sarcastic Retard]

Any help in permutations?I never seem to get those ones right,even if all else is correct.

Chapter 3

 

[asadalam]

Chapter 3

Thanks,after seeing that somehow i got 6/9 in one

 

[The Sarcastic Retard]

Thanks,after seeing that somehow i got 6/9 in one

The videos there are for clearing your basics and trick to crack tricky question patterns. Rest it depends on your knowledge of mathematics how you take the question. Keep practicing. You will score 9 on 9 easily in few days. ^_^
Good luck.

 

[sara kamal]

http://maxpapers.com/wp-content/uploads/2012/11/9709_s12_qp_32.pdf
anyone?plz explain Q9 part 2...i really dont get why they are integrating by parts twice??i have done like this:

 

[qwertypoiu]

http://maxpapers.com/wp-content/uploads/2012/11/9709_s12_qp_32.pdf
anyone?plz explain Q9 part 2...i really dont get why they are integrating by parts twice??i have done like this:
View attachment 53871

Note that
(ln x)^2 is not the same as ln(x^2)

 

[Jennifer4678]

Hey!! Can someone help me with Q10 , (b) (ii) please

 

[Aina]

http://onlineexamhelp.com/wp-content/uploads/2013/11/9709_s13_qp_32.pdf
help...q6 and q10 part ii
http://www.studentbounty.com/pastpa...athematics (9709)/2013 Jun/9709_s13_qp_31.pdf
plz tell me
Q7 part (b)
Q8 part (b)
plz solve this for me >>>>

 

[Tushar968]

hi can someone help me
when can i use ln while integrating?
how can i calculate the greatest value and least value of argument?
how can i expand (1+x)(2+2x)^-1

 

[ahmedish]

Are you asking about P3 or S1?
In P3 it is better just to review your answer and then proceed to the next.If you start checking whether your answer is correct it will take a lot of time and cause trouble later.Just review the working for any careless errors.In the end if you have time go through all the answers again,especially those you have your doubts on.In p3 it will be better to solve the easier questions first;those you're well acquainted with.

In S1,leave permutation and combination for the last.You should attempt other questions in order.I don't think there is any way to check your answers except for in normal distribution where you can check the probability by reversing.Again,it would be helpful to check in the end if time permits.

Try not to confuse yourself about a particular solution.There are times when you think what you've done is wrong although it's correct.

You can check your normal distribution answers with your calculator. Just go mode>stat>AC then shift 1>Dist>P(
enter your values any it does it for you. I use it in case I get the wrong values from the table. And thanks for your help anyway.

 

[..sacrifice4Revenge..]

Any past paoer question on trapezium rule.

 

[Wolfgangs]

Can someone please explain Q10 part 3?

http://maxpapers.com/wp-content/uploads/2012/11/9709_s12_qp_32.pdf