Maths AS PAPER 1 HELP PLEASE

[1992]

hello , can someone look at paper 1. O/N 2007. Question 4.ii) I canot show that 3a=8d.
Can someone do it with all the steps, as the march scheme just says the answer.

 

[intel1993]

as first term of gp is a
2nd term is a+4d
3rd term is a+14d

now according to the gp term formula
a+4d=ar
a+14d=ar^2

substitute r=a+4d/a frm the 1st equation into 2nd equation

a+14d=a* (a+4d/a)^2
a+14d= (a^2 + 8ad +16d^2)/a
a^2 +14d= a^2 + 8ad + 16d^2
6ad=16d^2
3a=8d (shown).........

 

[lee91]

cross multiply, it's easy.
a=a
1st arith term = 1st geome term

a+4d=ar
5th arith term = 1st geome term

a+14d=ar^2
15th arith term = 3rd geome term

a over (a+4d) is r, and is constant, look at the answer scheme again, i'm sure you know

 

[1992]

thankyou guys _

 

[1992]

Help need on O/N 2009 12 . Q4.i) ii) and iii) please

 

[khizarr]

i) for range , substitute the highest and smallest value of sinx that is ==>
5-3(1)= 2
5-3(-1)= 8
range= 8<f(x)<2 [ 2 and 8 are inclusive , i dont have the greater than and equal and less than and equal to sign on my keyboard]
ii) sin2x means the cycle will be completed at (pi) thus the period is (pi) .. plot the (pi/4), (pi/2), (3pi/4) and (pi). you'll get a wave like graph with the first curve is down and the second is up .
iii)it is not a one-one function therefore it has no inverse.
i think it may be helpful for you.

 

[1992]

Also help needed on Q 10. i)b) i have found the gradient. which is 2. then what i need to do??
and for the part b) ii) how shall i calculate the angle?? what does acute mean??

 

[1992]

i) for range , substitute the highest and smallest value of sinx that is ==>
5-3(1)= 2
5-3(-1)= 8
range= 8<f(x)<2 [ 2 and 8 are inclusive , i dont have the greater than and equal and less than and equal to sign on my keyboard]
ii) sin2x means the cycle will be completed at (pi) thus the period is (pi) .. plot the (pi/4), (pi/2), (3pi/4) and (pi). you'll get a wave like graph with the first curve is down and the second is up .
iii)it is not a one-one function therefore it has no inverse.
i think it may be helpful for you.

i cant draw the graph :S what does the 5 and the 3 mean??
from 5-3cos2x. could u draw it please

 

[poolstik]

tell me one thing, im doing AS level.. I have a math paper on wednesday, now since im studying in India, the time difference between me and some other country giving this same paper would obviously be different. are we allowed to post the paper? of post a topic like one of these to get the paper before hand? or is it considered cheating, and will be pulled up for it.. i'm new to this forum thing man, and i don't really know what this is really about.. How is being part of this beneficial to an extent of us getting good grades??

Please help.

 

[Zohaib Sherazi]

There are variants of each paper now so that this doesn't happen.

 

[khizarr]

err .. actually i dont kow how to draw it over here ! 5 and 3 are in the equation .. i just substituted the greatest and the least value of sin ..

 

[khizarr]

for Q10(c) : calculate the gradient of the curve that is 2 .. the gradient of the line is (1/2) when u make the equation in the y=mX + C form ..
: (tan inverse of 2) minus (tan inverse of .5)
: 63.435 - 26.565
: 36.87
final answer is 37 after rounding it off ..

 

[princesszahra]

@ sm1 above who mentioned abt time
its not allowed to post on forums within 24 hrs of exiam so cheating is not allowed!

 

[khizarr]

@poolstick, it does prove to be handful for you .. you put up any difficult question , you'll get different types of solutions u dont know and may be easier than the ones u use.. or if someone posts a question u've never encountered then the solution can be sort of a practice for u!

 

[PlanetMaster]

Since CIE is taking examinations according to GMT Time, you may post as you leave examination hall.

 

[obr***]

There are variants of each paper now so that this doesn't happen.

bt dose variants are quite similar
and secondly for maths dere are no variants-
itx just 4 phy chem bio etc[/quote]

 

[obr***]

In
5 - 3cos2x (0<x<pi)
5 means here we will start the graph- it will b treated lyk in normal graph as x-axis
3 means da amplitude of the graph
2 means no. of waves to draw in the range (0<x<2pi)
as da range abv is gven till pi so as 2 waves will form in 2pi so we will show 1 wave for pi
the -ve sign of 3 means that here we will make da reverse of a normal graph
lyk starting from values below till da lest value and then movig up



i hope dis will help u in making the graph!!!

 

[princesszahra]

dose variants are quite similar
and secondly for maths dere are no variants-
itx just 4 phy chem bio etc

There are variants of each paper now so that this doesn't happen.

bt dose variants are quite similar
and secondly for maths dere are no variants-
itx just 4 phy chem bio etc[/quote][/quote]

there r varients for maths too!!!!
moreover the varients r different!!!
standard is same!

 

[intel1993]

@princesszahra:
yes u saying right there r variants for maths tooo...
eg p11 p12 etc..