Mathematics: Post your doubts here!

[Mohamed Mirza]

Why is the order of rotational symmetry 1 in Q1 A http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_qp_22.pdf
I KNOW THAT THE ORDER OF SYMMETRY OF THE STAR IS 5 AND 2 FOR EACH RECTANGLE BUT HOW IS THE ANSWER 1 MAYBE SUBTRACTION?? PLEASE NEED HELP IN THIS Q

 

[Mohamed Mirza]

Because no matter how many degrees you rotate it , it is only symmetrical in one way.

Yeah but if you do so, your coordinates of the triangle will be diff than that of the marking sheet
0 ------ -1 1 -4
---------- x ===
1 ------ 0 4 1

 

[Mohamed Mirza]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_qp_22.pdf
Q11 part B
please help

 

[princess sofia]

Why is the order of rotational symmetry 1 in Q1 A http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_qp_22.pdf
I KNOW THAT THE ORDER OF SYMMETRY OF THE STAR IS 5 AND 2 FOR EACH RECTANGLE BUT HOW IS THE ANSWER 1 MAYBE SUBTRACTION?? PLEASE NEED HELP IN THIS Q

its order 2 , c star has 5 , no matter in which direction we turn it , its gonna b da same bt 4 rectangle the order is 2 , so we ll be takng order 2

 

[Karim Nabil]

Thanx alot bro Jazak Allah Khair

you are most welcome!

 

[princess sofia]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_qp_22.pdf
Q11 part B
please help

divide the shape into 2 , one rectangle n other triangle , the base of triangle is equal to the base of rectangle , nw use pythogrus theorum to work out base of triangle n than equal it to PT

 

[Mohamed Mirza]

its order 2 , c star has 5 , no matter in which direction we turn it , its gonna b da same bt 4 rectangle the order is 2 , so we ll be takng order 2

The marking sheet says 1 http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_ms_22.pdf

 

[princess sofia]

The marking sheet says 1 http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_ms_22.pdf

THN I DNT HAVE ANY IDEA HOW ??

 

[Mohamed Mirza]

divide the shape into 2 , one rectangle n other triangle , the base of triangle is equal to the base of rectangle , nw use pythogrus theorum to work out base of triangle n than equal it to PT

how is it possible to use pythagoras theorem whem we are only given one side

 

[Mohamed Mirza]

THN I DNT HAVE ANY IDEA HOW ??

if you find why please tell me

 

[princess sofia]

how is it possible to use pythagoras theorem whem we are only given one side

 

[princess sofia]

actually isnt their a mistake in Pythagoras rule shouldn't the be minused instead of adding

i ddnt get wt u sayng

 

[Mahwish Khalid]

Is this correct?

 

[shoaib672002]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_qp_22.pdf
http://papers.xtremepapers.com/CIE/Cambridge%20IGCSE/Mathematics%20(0580)/0580_s10_ms_22.pdf
QUESTION NO. 8
How

 

[Mahwish Khalid]

PLEASE SHOW THE WORKINGS.

 

[Mahwish Khalid]

u have

to include the intersection for the first one since they said the whole set A

Oh okay, thanks!

 

[shoaib672002]

For A- rearrange the equation so the functions are not on the same side: sinx-cosx=0 is sinx=cosx
(As both sides are already shown graphically, x would be the x coordinate of the point of intersection.) you need to find the difference between the 2 graphs is 0. Where they intersect?
30+60=90/2=45
B- (to solve for x in this equation you should translate the cox graph into a cosx+0.5 graph)
you need to estimate the diif between the 2 curves is 0.5
In the olevel, they will give you a tracing paper where you can plot the points
once plotted, check using trial and error
i got x to be 66

Could u draw and show

 

[DarkEclipse]

Yeah but if you do so, your coordinates of the triangle will be diff than that of the marking sheet
0 ------ -1 1 -4
---------- x ===
1 ------ 0 4 1

I have no idea what you're doing, but I don't bother with co-ordinates in symmetry.
However, I think what you're saying applies to plain old order of symmetry, but this is the rotational order. They're not the same.

 

[DarkEclipse]

Can you show me how its rotated about (4,4)

OH! I thought you were talking about the star.
Anyway, post the whole question paper, and not a screenshot, and I'll get back to you tomorrow.
I may have the answer, but I want to check the mark scheme to be sure.

 

[saif mahmoud]

I really need help in a couple of Qs
View attachment 40963 How is the order of rotation 1???



View attachment 40964 Parts A,B and c-ii



View attachment 40965 ?????????

These are the only Qs im stuck on, and inshallah we all get A* this Tuesday (paper 2)

for the first ques it has to be one because if u make this diagram upside down it will not look identical as the original one so it has to be 1 .