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[shazmina]

Any term in this sequence is equal to the term before it plus two times the term two before it.

So the term after 3413, 6827 is

6827 + 2*3413 = 13653.


Now call x the term before 3413, 6827.

Then 6827 = 3413 + 2x

--> x = (6827-3413)/2 = 1707

Mnay tnxs......it ws rele vry helpful

 

[notnek01]

OooO ok for the next step of http://papers.xtremepapers.com/CIE/Cambridge%20IGCSE/Mathematics%20(0580)/0580_w08_qp_4.pdf q.10 b ii i did 100(100+1) but its wrong idk how im supposed to think !!

2 + 4 + 6 + ... + 200

This is actually the first 100 even numbers not the first 200. The first 200 even numbers are

2 + 4 + 6 + ... + 400

 

[$$AK$$]

Useful formulas:

Arithmetic sequences with a constant first (common) difference: nth term = a + (n-1)d

where d is the common difference and a is the first term.

e.g. 3, 7, 11, 15, 19, ...

The common difference is 4 so the nth term is 3 + (n-1)*4 = 4n - 1


Quadratic sequences with a constant second difference: nth term = a + (n-1)d + 0.5(n-1)(n-2)c

where a is the first term, d is the difference between the first two terms and c is the constant second difference.

But my preferred method...

A quadratic sequence has nth term of the form an^2+bn+c. a is the second difference divided by 2 and you can find b and c by substituting values and solving the equations.

E.g. 4, 6, 10, 16, 24, ...

First differences are 2, 4, 6, 8, ... so second difference is constant (which means it's a quadratic sequences) and is equal to 2.

So a=2/2 = 1

Then the nth term must be n^2+bn+c. Substitute n=1 and n=2:

n=1 : 1 + b + c = 4
n=2 : 4 + 2b + c = 6

Solve these equations to find b and c.

Thank you alot,
thats helped me alot.
what are the main topics for paper 4?

 

[Majd Aldeen]

need help in M\J 2009 paper 4 q4e
same year q10 g

 

[shazmina]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_qp_42.pdf could u plzzz let me knw hw to solve de question no 10 part (d).... ie de sequence

 

[notnek01]

oh okay so i attached my working of the sn thing so far but idk how to continue

You made a mistake on the 2nd line:

(n-1+2) = (n+1)

You said (n-1+2)=n

Also, don't start with the whole equation because that's what you're trying to prove. Start with the left-hand-side of the equation and show it equals the right-hand-side.

For example, I could prove 1=2 by using a similar method to what you have done:

1 = 2 (multiply both sides by 0)
0 = 0

So 1=2.

 

[notnek01]

Thank you alot,
thats helped me alot.
what are the main topics for paper 4?

How do I know?

 

[notnek01]

need help in M\J 2009 paper 4 q4e
same year q10 g

There is no Q4e.

 

[notnek01]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_qp_42.pdf could u plzzz let me knw hw to solve de question no 10 part (d).... ie de sequence

Look at the sequence:

0, 2, 5, 9, 14, ...

Each time, the difference goes up by 1.

You need to find two consecutive terms where the difference is 30. Just continue the sequence to find this value.

You could use algebra but it would be a waste of time.

 

[Majd Aldeen]

There is no Q4e.

oh sorry its Q5e

 

[inquisitiveness]

btwi just remembered,would they ever ask us to find the volume of a circle.....i knwo the volume of sphere thing but just normal circle like we find area then multiply it with length or somehting

 

[notnek01]

oh sorry its Q5e

You just need to write down any graph that doesn't intersect y=(x/2)-(2/x).

y=x is the most obvious answer.

 

[shazmina]

Look at the sequence:

0, 2, 5, 9, 14, ...

Each time, the difference goes up by 1.

You need to find two consecutive terms where the difference is 30. Just continue the sequence to find this value.

You could use algebra but it would be a waste of time.

tnx u sooo mch , it ws rele vry helpful...

 

[notnek01]

btwi just remembered,would they ever ask us to find the volume of a circle.....i knwo the volume of sphere thing but just normal circle like we find area then multiply it with length or somehting

Do you mean a cylinder?

You can't find the volume of a circle since it is a 2d shape.

 

[inquisitiveness]

what is 2n-1 multiplied by 2n? is i t 4n^2-2n?

 

[inquisitiveness]

Do you mean a cylinder?

You can't find the volume of a circle since it is a 2d shape.

oh okay thanks,no i know the cylinder formula

 

[Mohammed salik]

Sir a Question? M/J 2011 v 43 Q 10 b(ii)? Plz Thanx

 

[notnek01]

what is 2n-1 multiplied by 2n? is i t 4n^2-2n?

Yes.

 

[notnek01]

Sir a Question? M/J 2011 v 43 Q 10 b(ii)? Plz Thanx

What do you notice about the sums of the integers and the sums of the cubes?

Sum of integers: 1, 3, 6, 10, ...

Sum of cubes: 1, 9, 36, 100, ...

The terms in the 'sum of cubes' are the terms in the 'sum of integers' squared.

Does that help?

 

[Mohammed salik]

What do you notice about the sums of the integers and the sums of the cubes?

Sum of integers: 1, 3, 6, 10, ...

Sum of cubes: 1, 9, 36, 100, ...

The terms in the 'sum of cubes' are the terms in the 'sum of integers' squared.

Does that help?

Sir that is Q11 b(ii) , I need q10b(ii)
Thanxx anyways