Mathematics: Post your doubts here!

[masterex567]

hey masterex567 how in the fourth one 6 equilateral triangles are there?? only 3 are there

Oh yes forgot to explain that. That was a trick. A regular hexagon has 6 equilateral triangles, if you notice the shaded area in the diagram is actually equal to one of these 6 regular triangles.

 

[AnonymousX9]

What do you guys think? Will Paper 42 be very hard or moderate? I'm nervous although my paper 2 was really good.

 

[misscute406]

Oh yes forgot to explain that. That was a trick. A regular hexagon has 6 equilateral triangles, if you notice the shaded area in the diagram is actually equal to one of these 6 regular triangles.

dint get you!! Kindly explain again!!

 

[misscute406]

masterex567 Please explain the last one again yaar please!! Can't understand!!

 

[masterex567]

masterex567 Please explain the last one again yaar please!! Can't understand!!

a hexagon is made of 6 equilateral triangles. if you get the area of 1 of these 6 equilateral triangles, you will find out that it is indeed equal to the shaded area of the whole triangle shown in the paper.
You had to assume that it was equal to 1/6 of these 6 equilateral triangles

 

[masterex567]

Need help in these questions

1) may june 13 v.42 Q.4 (d), Q.9 (b) ii , Q.11 (d) iii

question 4.
they are asking for MAJOR arc AC, which spans from A to C CLOCKWISE. Now if MOB is 39, OBN is also 39. Also AOM is 39 and ONC is 39. So angle AOC will be 360 - 4 * 39. Now calculate arc length using (360-4*39) as the angle.
9 b ii
now first of all the volume of the water in bucket which is 12 litre is responsible for the 5 mm height.
So we know volume of something is the cross sectional area * height.
Hence 12000 cm3 (converted from litres to cm3) = pi*r^2 * 0.5 (converted 5mm to cm). Use simple algebra to find r, as 87.4. Now it should be correct to nearest cm so answer is 87.

11 d iii
Now since these are similar triangles they have equal angles, and in previous part we calculated the angle as 18.4 degrees.
Now to make a whole circle of 360 degrees, we can find how many of these angles can be drawn to make 360 degrees by 360/18.4, which is 19.
Now one 18.4 degree angle makes 1 triangle, hence makes P1, P2, P3. etc. So similarly it will make "19" which we calculated triangles as (n-1) on diagram.
n-1 = 19 so n = 20.

 

[misscute406]

a hexagon is made of 6 equilateral triangles. if you get the area of 1 of these 6 equilateral triangles, you will find out that it is indeed equal to the shaded area of the whole triangle shown in the paper.
You had to assume that it was equal to 1/6 of these 6 equilateral triangles

ooh thank you so much dude!!

 

[NOneed2speedd]

question 4.
they are asking for MAJOR arc AC, which spans from A to C CLOCKWISE. Now if MOB is 39, OBN is also 39. Also AOM is 39 and ONC is 39. So angle AOC will be 360 - 4 * 39. Now calculate arc length using (360-4*39) as the angle.
9 b ii
now first of all the volume of the water in bucket which is 12 litre is responsible for the 5 mm height.
So we know volume of something is the cross sectional area * height.
Hence 12000 cm3 (converted from litres to cm3) = pi*r^2 * 0.5 (converted 5mm to cm). Use simple algebra to find r, as 87.4. Now it should be correct to nearest cm so answer is 87.

11 d iii
Now since these are similar triangles they have equal angles, and in previous part we calculated the angle as 18.4 degrees.
Now to make a whole circle of 360 degrees, we can find how many of these angles can be drawn to make 360 degrees by 360/18.4, which is 19.
Now one 18.4 degree angle makes 1 triangle, hence makes P1, P2, P3. etc. So similarly it will make "19" which we calculated triangles as (n-1) on diagram.
n-1 = 19 so n = 20.

Whoa! .. Thanks man...
best of luck for ur exam...In Shah Allah we all will get A*

 

[Lana19984]

Part (c)
(I've never faced any trouble in this kind of questions. .. don't knw why i can't solve this one )

which year is this ?

 

[Lana19984]

guys a question about graphs , do we plot the point with Xs or Dots ?

 

[Saad the Paki]

guys a question about graphs , do we plot the point with Xs or Dots ?

Both are acceptable..
But small crosses are preferrabale

 

[misscute406]

Guys I am not able to understand the mark scheme....0580/43/m/j/13 ques 3c(i) can someone send me the worked out answer please

 

[loaie Amgad]

Guys I am not able to understand the mark scheme....0580/43/m/j/13 ques 3c(i) can someone send me the worked out answer please

oh man its a graph
hhhhh take it as a rule m scheme cant help with graphs....
Just try to your furthest extent to be sure of your work.....

 

[misscute406]

Hey I am bad at linear programming....that's why!! Kindly help someone?? Saad the Paki Lana19984 can you help me

 

[HKHOHOHOHOHL]

Anyone givng IGCSE MAY JUNE 2015 IGCSE MATHEMATICS ?0580? 41/42??? OR ANYONE as appeared in 41/42 Please contact .... [email protected] !! Thanks in Advance!!!

 

[masterex567]

What's the minimum mark required for grade column for? Like for paper 2 out of 70 it's 55 for example for A.
Does that mean if you get below 55 in that paper you can't get an A as final grade?

 

[misscute406]

What's the minimum mark required for grade column for? Like for paper 2 out of 70 it's 55 for example for A.
Does that mean if you get below 55 in that paper you can't get an A as final grade?

I don't now but currently answer my prev question regarding Inequality please man!!

 

[NOneed2speedd]

What's the minimum mark required for grade column for? Like for paper 2 out of 70 it's 55 for example for A.
Does that mean if you get below 55 in that paper you can't get an A as final grade?

Frm what I've heard u should get 88% out of 200 to get A* (as per 14 grade threshold)
now matter if u do bad in p.2 but good in p4 or vice versa. .

 

[misscute406]

Frm what I've heard u should get 88% out of 200 to get A* (as per 14 grade threshold)
now matter if u do bad in p.2 but good in p4 or vice versa. .

Hey help me out in my prev question on linear programming please

 

[NOneed2speedd]

Hey help me out in my prev question on linear programming please

hope u understand