Maths, Addmaths and Statistics: Post your doubts here!

[asadalam]

For locus questions
Do we have to indicate on our diagrams tht whether this locus refers to locus given as 1(in exams) or 2(as also given in questions).I mean do we have to give a mark or arrow and write tht this specific locus is in response to the 1st condition or 2nd e.t.c

No

 

[M.Omar]

No

Sure?any general reason ?
Am repeating coz I usually like a detailed and colourful response

 

[peacce]

http://papers.xtremepapers.com/CIE/...Calculator Version) (4024)/4024_s13_qp_12.pdf
q.22 kirann

 

[mohammad ahmed]

http://papers.xtremepapers.com/CIE/...Calculator Version) (4024)/4024_w12_qp_11.pdf

q22 c and d

 

[kirann]

122?

148

 

[asadalam]

Sure?any general reason ?
Am repeating coz I usually like a detailed and colourful response

NO

Colorful for you

 

[exploded diper]

Extend and end it at 20.For these polygons we have to start from the first class i.e 0 and end at the last i.e 20,if it were 16<t<18 at the end we would extend and stop it at 18.But do extend till the axis.

sp if we extend it to twenty we do not pass it through 18....
other wise it would be below 2..can u draw it .....when u have time ...or if u have time tht is.....

 

[Abdul Hanan]

148

sin32 and sin 148 have same answer....
180-32=148
sin(x)=sin(180-x)
e.g sin20=sin160
sin10=sin170

 

[asadalam]

sp if we extend it to twenty we do not pass it through 18....
other wise it would be below 2..can u draw it .....when u have time ...or if u have time tht is.....

 

[FLRNAB]

It means any equivalent constants e. 2x4=8.5x4=20 8/20 and 2/5 are the same .

I wrote 4/10 and 4/100?

 

[M.Omar]

NO

Colorful for you

For sure...

 

[asadalam]

I wrote 4/10 and 4/100?

It said 0.4 so 4/10 is right but it had to be 40/100 in the other one

 

[M.Omar]

View attachment 43874

Wait what?
The pt has to be plotted at the right frequency tht is 2 and at the mid pt of 16 and 20 i.e 18 and then we cud further join it t 20 on axis but the further part is ignored by the examiner ..Read it in MS of 2008 ppr so the Graph of Zain rocks is right in the premise of its req tht is correct plotted pts and joing them with a straight line

 

[princess Anu]

22(b)?

 

[asadalam]

Wait what?
The pt has to be plotted at the right frequency tht is 2 and at the mid pt of 16 and 20 i.e 18 and then we cud further join it t 20 on axis but the further part is ignored by the examiner ..Read it in MS of 2008 ppr so the Graph of Zain rocks is right in the premise of its req tht is correct plotted pts and joing them with a straight line

I see,but i showed it from the classified,though i guess we dont have to extend,but its fine to.Here we use mid but in cumulative graphs we plot at extreme right i.e if 6<t<8 we plot at 8?

 

[M.Omar]

Also if we have qualms abt writing an answer in d.p or leaving it as fraction,how many sig fig or d.p shud we write in our answer if we consider the latter option
2 or 3?

 

[asadalam]

Also if we have qualms abt writing an answer in d.p or leaving it as fraction,how many sig fig or d.p shud we write in our answer if we consider the latter option
2 or 3?

3 is better and if q is in fraction leave answer in fraction like the initial few questions.

 

[M.Omar]

I see,but i showed it from the classified,though i guess we dont have to extend,but its fine to.Here we use mid but in cumulative graphs we plot at extreme right i.e if 6<t<8 we plot at 8?

Yes here we use mid but in cumulative curves they don't give in the form t<x<v they simply give in form x<=t so we simply plot tht x point in our curve plot point "t" .Nothing to it

 

[asadalam]

Yes here we use mid but in cumulative curves they don't give in the form t<x<v they simply give in form x<=t so we simply plot tht x point in our curve .Nothing to it

Yeah i meant that but i couldnt show the sign,thanks

 

[M.Omar]

BTW, this is pretty stupid but I get stuck on this sometimes.

How do we know which to apply of 80/100 or 100/120? And 100/80 or 120/100?

Which situation mein which applies (assuming it's 20% loss profit whatever)

Don't take on this metod;i assume u wud be memorizing where to put 100 over the value and vice cersa
Just take it like this:
If they say selling price=12
percentage prf =20%
CP=X
so X+20%X=12
X+0.2X=12
1.2X=12(u get the rest)
Conversely if they say tht 20 % profit leads to a sale price
CP=120
SP=X
again
CP+%prf=SP
X+20%X=SP
120+0.2*120=SP(u do the subsequent math)
So for me I generally prefer this "algebraic method"