Mathematics: Post your doubts here!

[Aishy Vimal]

For y < ax+b or y <= ax+b, the satisfied region is below the boundary line so the unwanted region is above the boundary line.

Similarly, for y > ax+b or y >= ax+b, the unwanted region is below the boundary line.

thank you so much!!!!

 

[Aishy Vimal]

could someone help me with venn diagrams? or like have a tutorial? i have trouble figuring out how to fill up the diagram

 

[notnek01]

could someone help me with venn diagrams? or like have a tutorial? i have trouble figuring out how to fill up the diagram

Can you post some example question(s)?

I answered a question in the previous page of this thread (p.147) that may help.

 

[Aishy Vimal]

Can you post some example question(s)?

I answered a question in the previous page of this thread (p.147) that may help.

like in w2011 v23 question 17

 

[notnek01]

like in w2011 v23 question 17

Firstly, the total number is 20 and the union is 17 (the circles area) so that means that there are 3 students outside the union (write a 3 outside the circles area).

Now the union is made up of three sections: "Rugby but not football", "both" and "Football but not rugby".

n(R) = 13: This means that the R circle will total 13. But we know that the three sections add up to 17. This means that the "Football but not rugby section" must be 17-13=4.

n(F) = 11: This means that the F circle will total 11. So the "both" section must be 11-4=7.

Can you finish it from here?

 

[ZaqZainab]

That's intersection not union.

It is union!

 

[notnek01]

It is union!

"only B but not the part where b is intersecting A" - This is A' ∩ B (intersection).

But you replied to the post which asked about "A' U B" (union).

 

[ZaqZainab]

Damn it I am sorry to whoever i replied it is the whole Venn Diagram disincluding the part which is only A! and yeah thanks to correct me!

 

[Rockzstar]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s12_qp_22.pdf

can any1 plz explain question 19 a) b) c)
what does
has no inverse,
is the identity matrix,
represents a stretch with factor 3 and the x axis invariant.
MEAN ???

 

[notnek01]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s12_qp_22.pdf

can any1 plz explain question 19 a) b) c)
what does
has no inverse,
is the identity matrix,
represents a stretch with factor 3 and the x axis invariant.
MEAN ???

a) A matrix has no inverse if it's determinant is 0.

b) The identity matrix: http://sophialearning.s3.amazonaws....675676&Signature=bUBdDqUC3naLK4G9OwtQHHYv8pI=

c) How do you find a transformation matrix if you know the transformation?

 

[Rockzstar]

the

a) A matrix has no inverse if it's determinant is 0.

b) The identity matrix: http://sophialearning.s3.amazonaws.com/ckeditor_assets/1350/content/Identity-Matrix-2x2.png?AWSAccessKeyId=AKIAJBJJNCQ5MHXCIRUA&Expires=1367675676&Signature=bUBdDqUC3naLK4G9OwtQHHYv8pI=

c) How do you find a transformation matrix if you know the transformation?

the website doesnt open !

 

[notnek01]

the

the website doesnt open !

The 2x2 identity matrix has first row (1,0) and second row (0,1). Google image it if you're still not sure.

 

[Rockzstar]

The 2x2 identity matrix has first row (1,0) and second row (0,1). Google image it if you're still not sure.

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s11_qp_22.pdf

the first question can u please explain

 

[tweetie]

16 b:
PQ: .5a - .5c
position vector of M = OM
= c + .5a + .5(.5a-.5c)
= c + .5a + .25a - .25c
= 0.75c + .75a
18 a:
A (7,0) B (5,3)
midpoint of AB: (1/2(7+5), 1/2(0+3)
= (6,1.5)

19:
b h(2x-3)
hh(x) = 2(2x-3)-3
= 4x-6-3
= 4x-9

c. fg(x+1) = f(2^x+(1))
= (2^x+1)^2
= 2^2(x+1)

thank you so much for the help...but i didnt understand how to do the 16th one :/ :/

 

[notnek01]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s11_qp_22.pdf

the first question can u please explain

You could use your calculator to find C (inverse cos 4/5) and then do 180-90-C to find angle A.

 

[Anonimous12345]

Salams. I have a doubt if someone can plz help.
Well it just counts 1 mark however i dont know how to do it for all cases.
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w06_qp_1.pdf
its question 16, b)
3^x=1/81

Tks.

 

[notnek01]

Salams. I have a doubt if someone can plz help.
Well it just counts 1 mark however i dont know how to do it for all cases.
http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w06_qp_1.pdf
its question 16, b)
3^x=1/81

Tks.

You need to make 1/81 into a power of 3.

Firstly, 81 = 3 x 3 x 3 x 3 = 3^4.

So 1/81 = 1/3^4

And using the negative indices rule, this is equal to 3^(-4).

So x = -4.

Does that make sense?

 

[Anonimous12345]

Right. Thank you

 

[Master Minds]

thank you so much for the help...but i didnt understand how to do the 16th one :/ :/

position vector of M means OM. PQ= 0.5a-0.5c (as calculated in part a)
so starting from OC= c
now CP= 0.5 a
now add half PQ = .25a-.25c
add all of them : c+.5a+.25a-.25c
= .75c + .75 a
Alternatively
add OA + AQ + (-1/2)PQ
here you take (-1/2)PQ because in this way you will be moving from Q to M making QP instead of PQ as found in part a

 

[tweetie]

position vector of M means OM. PQ= 0.5a-0.5c (as calculated in part a)
so starting from OC= c
now CP= 0.5 a
now add half PQ = .25a-.25c
add all of them : c+.5a+.25a-.25c
= .75c + .75 a
Alternatively
add OA + AQ + (-1/2)PQ
here you take (-1/2)PQ because in this way you will be moving from Q to M making QP instead of PQ as found in part a

i understood (Y) thanx a lot