Mathematics: Post your doubts here!

[Ebrahim12]

But this has just bounced off the surface, not reaching the bottom...the one in the question first reached the bottom of the tank and then returned back to rise above the water surface

What do you mean it didn't reach the bottom? it did bounce off the bottom of the tank. The one in the question as dropped from a height above the surface of the water and it didn't exceed that height.

 

[A*****]

What do you mean it didn't reach the bottom? it did bounce off the bottom of the tank. The one in the question as dropped from a height above the surface of the water and it didn't exceed that height.

Alright

 

[Khitan]

Can anyone help please ?My solution is als attached what is my mistake?

 

[A*****]

Can anyone help please ?My solution is als attached what is my mistake?

Your solution is the answer to the statement 'if ALL china mugs are not together'. That means that 2 can be together but for all separated, the thing which must be taken into account is that not even 2 must be together. For this there is a simple concept which works every time. First see in how many ways plastic cups can be arranged, which is 6! China cups are to be placed in between them so they have 7 possible positions. Hence, their number of arrangements will be 7P3. Therefore the answer will be 6!x7P3

 

[PLAyer2002002]

Don't you have the unsolved physics p4? Also what about physics p5?

i coudnt find anywhere p5 and i didnt find an unsolved version of this either.

 

[PLAyer2002002]

Don't you have the unsolved physics p4? Also what about physics p5?

all u have to do is cut out the parts with the answer using any photoeditor tool like Paint. belive me it will be easier than looking for an unsolved paper

 

[PLAyer2002002]

UPDATED



Mark schemes are not yet released and i cant find p3 or p1 yet


only the papers have been released till now

MATH PAPER 4 AS: https://www.file4.net/f-SyG
MATH PAPER 1 AS: https://www.file4.net/f-SyF
Math P3 AS : https://www.file4.net/f-SLe
Math p6 A2: https://www.file4.net/f-SLf



BIOLOGY AS P2: https://www.file4.net/f-SPR


CHEMISTRY AS P2: https://www.file4.net/f-SPU




PHYSICS PAPER 2 AS: https://www.file4.net/f-SFt

Physics P4 A2:
Page 1: https://www.file4.net/f-SLg
Page 2: https://www.file4.net/f-SLh
Page 3: https://www.file4.net/f-SLi
Page 4: https://www.file4.net/f-SLj
Page 5: https://www.file4.net/f-SLk
Page 6: https://www.file4.net/f-SLl
Page 7: https://www.file4.net/f-SLm
Page 8: https://www.file4.net/f-SLn
Page 9: https://www.file4.net/f-SLo
Page 10: https://www.file4.net/f-SLp
Page 11: https://www.file4.net/f-SLq
Page 12: https://www.file4.net/f-SLr
Page 13: https://www.file4.net/f-SLs
Page 14: https://www.file4.net/f-SLt
Page 15: https://www.file4.net/f-SLu
Page 16: https://www.file4.net/f-SLv
Page 17: https://www.file4.net/f-SLw
Page 18: https://www.file4.net/f-SLx
Page 19: https://www.file4.net/f-SLy
Page 20: https://www.file4.net/f-SLz
Page 21: https://www.file4.net/f-SLA
Page 22: https://www.file4.net/f-SLC
Page 23: https://www.file4.net/f-SLD
Page 24: https://www.file4.net/f-SLE
Physics P4 A2: https://www.file4.net/f-SPW

 

[Shemyaa]

HELP PLEASE IM JUST CONFUSED IN A VERY SMALL PART

So this question is like the last part of a long question and ill summarise things here
There are two parallel lines, one is a tangent to the curve and has the eqn y=0.5x and another lone called AB that intersects the X axis with eqn: (x-1)/2
The question asked to find the perpendicular distance between the parallel lines.
I understood the part it said tan theta =gradient and I got that
I just dont get what does sin have to do with the distance

MARKING SCHEME

 

[Ebrahim12]

HELP PLEASE IM JUST CONFUSED IN A VERY SMALL PART
View attachment 64622
So this question is like the last part of a long question and ill summarise things here
There are two parallel lines, one is a tangent to the curve and has the eqn y=0.5x and another lone called AB that intersects the X axis with eqn: (x-1)/2
The question asked to find the perpendicular distance between the parallel lines.
I understood the part it said tan theta =gradient and I got that
I just dont get what does sin have to do with the distance
View attachment 64623
MARKING SCHEME
View attachment 64624

Graph of the two lines, perpendicular distance d and theta the angle of the tangent with the x-axis.

Form the line equation:
tan(theta) = gradient of tangent
tan(theta) = 0.5

You can get sin from tan by:

1. Drawing a triangle where tan(theta) = 0.5, opp side = 1 and adj side = 2
2. Use Pythagoras's theorem for the third side, hypo = root5
3. Calculate sin = opp/hypo

sin(theta) = 1/root5

From the graph:
sin(theta) = d/1
1/root5 = d/1
therefore, d = 1/root5

 

[A*****]

If any one has done Maths Feb/March 19 Paper 62 then plz match ur answers with me and do tell me where there is a conflict.
1) i) 0.248
ii) 0.362
2) i) 328
ii) 58.2
3) i) 0.252
ii) 145
4) i) 1/15
ii) 2.33 and 1.16
5) ii) 72kg and 15kg
6) i) 0.117
ii) 3
iii) 0.173
7) i) 30240
ii) 360
iii) 5880
iv) 4
v) 16

 

[Ebrahim12]

If any one has done Maths Feb/March 19 Paper 62 then plz match ur answers with me and do tell me where there is a conflict.
1) i) 0.248
ii) 0.362
2) i) 328
ii) 58.2
3) i) 0.252
ii) 145
4) i) 1/15
ii) 2.33 and 1.16
5) ii) 72kg and 15kg
6) i) 0.117
ii) 3
iii) 0.173
7) i) 30240
ii) 360
iii) 5880
iv) 4
v) 16

Same except:

3(ii) 135
K has to be smaller than the mean(140) for the probability of being greater than it to be more than 0.5(0.675)

6(ii) 7
Prob(atleast one) = 1 - Prob(none)
1 - 0.65^n > 0.95
solving for n gives me 7

 

[Shemyaa]

View attachment 64627

Graph of the two lines, perpendicular distance d and theta the angle of the tangent with the x-axis.

Form the line equation:
tan(theta) = gradient of tangent
tan(theta) = 0.5

You can get sin from tan by:

1. Drawing a triangle where tan(theta) = 0.5, opp side = 1 and adj side = 2
2. Use Pythagoras's theorem for the third side, hypo = root5
3. Calculate sin = opp/hypo

sin(theta) = 1/root5

From the graph:
sin(theta) = d/1
1/root5 = d/1
therefore, d = 1/root5

Ahhh thanks
Its harder when you have to visualise it :')

 

[A*****]

Same except:

3(ii) 135
K has to be smaller than the mean(140) for the probability of being greater than it be more than 0.5(0.675)

6(ii) 7
Prob(atleast one) = 1 - Prob(none)
1 - 0.65^n > 0.95
solving for n gives me 7

Alright thanks! I've spotted my mistakes

 

[Ebrahim12]

Ahhh thanks
Its harder when you have to visualise it :')

You can make the same sketch on exam paper

 

[Ebrahim12]

Alright thanks! I've spotted my mistakes

You have your p3 answers?

Mine:
1
(ii)12.2
2
(ii)4^(1/5)
3
(i)tan = (2root2 - 1)/(1 - root6)
(ii)128.4, 308.4
6
y = e^(x/2)
7
(a)1 - i and 20/8 + (4/8)i
8
(i)2- 4/(2+x) + 6/(3-2x)
(ii)2 + (7/3)x + (7/18)x^2
9
(i)56.9
(ii)(11/7, -5/7 , 0) + lambda(1, -3, -7)
10
(i)8/21
(ii)1.183

 

[A*****]

You have your p3 answers?

Mine:
1
(ii)12.2
2
(ii)4^(1/5)
3
(i)tan = (2root2 - 1)/(1 - root6)
(ii)128.4, 308.4
6
y = e^(x/2)
7
(a)1 - i and 20/8 + (4/8)i
8
(i)2- 4/(2+x) + 6/(3-2x)
(ii)2 + (7/3)x + (7/18)x^2
9
(i)56.9
(ii)(11/7, -5/7 , 0) + lambda(1, -3, -7)
10
(i)8/21
(ii)1.183

I'll do it in a day or two
Btw are u giving A2 only or composite?

 

[Ebrahim12]

I'll do it in a day or two
Btw are u giving A2 only or composite?

A2 , already gave AS. You?

 

[A*****]

A2 , already gave AS. You?

Composite

 

[Ebrahim12]

Composite

Ah, good luck

 

[A*****]

You have your p3 answers?

Mine:
1
(ii)12.2
2
(ii)4^(1/5)
3
(i)tan = (2root2 - 1)/(1 - root6)
(ii)128.4, 308.4
6
y = e^(x/2)
7
(a)1 - i and 20/8 + (4/8)i
8
(i)2- 4/(2+x) + 6/(3-2x)
(ii)2 + (7/3)x + (7/18)x^2
9
(i)56.9
(ii)(11/7, -5/7 , 0) + lambda(1, -3, -7)
10
(i)8/21
(ii)1.183

All of my answers match yours except 9 ii but for such type of questions multiple answers are given in the ms. Right?
And plz share the solution of Q5