Mathematics: Post your doubts here!

[syed1995]

no way m1 is much easier s1 is hard enough


i guess we will have to siscuss all the papers by friday with three consecutive papers no time will be there. half grade decided by 14th may and still going on to 11th june cie logic -_-

I will try and complete my chemistry physics by this Monday .. and then concentrate on Maths P1.. I haven't done even a single Maths P1 yet :\

My Chem Practical is on the 23rd..

 

[daviruss]

plzz help in number 6 can any one solve it for me plzz http://papers.xtremepapers.com/CIE/...AS Level/Mathematics (9709)/9709_s08_qp_3.pdf

 

[A star]

I will try and complete my chemistry physics by this Monday .. and then concentrate on Maths P1.. I haven't done even a single Maths P1 yet :\

My Chem Practical is on the 23rd..

i dont even know when my practical is
well i dont have gp so have three papers in three days

 

[syed1995]

i dont even know when my practical is
well i dont have gp so have three papers in three days

haha .. GP is compulsory at our school.. honestly as long as i give Chemistry AL first and then GP it will be all good.. else i am screwed.. :\ lol both in morning

in P1.. Functions is where i lose most marks.. I don't know why but I lose marks in this.

 

[applepie1996]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_31.pdf

its question 9 .... problem is in the first few steps...... how come C = - 3 ? its coming 6 on myside (when doing the partial fractions) and finding A = 2 and B = 1 ?

applepie1996

or any one ? thanks alot

okay
i will try to do it

 

[applepie1996]

View attachment 23718

ok here goes to find the limits of this curve y= sin cube 2x cos cube 2x we will put y=0 as on the x axis y=o
0= cos cube2x sin cube 2x o=sin cube 2x
sin cube 2x = 0 0 = cos cube 2x
x=0 2x=pi/2

x= pi/4

so the limits be pi/4 and 0

by substituting u= sin2x
du/dx = 2cos2x
du= 2cos2x dx

now substituting

(cos cube 2x)( u^3) (1/ 2cos2x) <----------- where this is du
one cos would be cut by the cos in the denominator
u^3 (cos square 2x)/2
remember that cos square x = 1-sin square x
so cos square x = 1-sin square x
so
cos square 2x = 1-sin square 2x
and sin 2x =u
so
cos square 2x= 1- u^2
then the total thing wud be
1/2 integral of u^3(1-u^2)
1/2 integral of u^3 - u^5
1/2 (( u^4)/4 - (u^6)/6)
now open u as sin2x
1/2 (( sin 2x^4)/4 - (sin 2x^6)/6)
1/2 (1/4- 1/6)
1/2 (1/12)
1/24

No need to thank me
because i didn't solve it
Rutzaba solved it for me

 

[Rutzaba]

ok here goes to find the limits of this curve y= sin cube 2x cos cube 2x we will put y=0 as on the x axis y=o
0= cos cube2x sin cube 2x o=sin cube 2x
sin cube 2x = 0 0 = cos cube 2x
x=0 2x=pi/2

x= pi/4

so the limits be pi/4 and 0

by substituting u= sin2x
du/dx = 2cos2x
du= 2cos2x dx

now substituting

(cos cube 2x)( u^3) (1/ 2cos2x) <----------- where this is du
one cos would be cut by the cos in the denominator
u^3 (cos square 2x)/2
remember that cos square x = 1-sin square x
so cos square x = 1-sin square x
so
cos square 2x = 1-sin square 2x
and sin 2x =u
so
cos square 2x= 1- u^2
then the total thing wud be
1/2 integral of u^3(1-u^2)
1/2 integral of u^3 - u^5
1/2 (( u^4)/4 - (u^6)/6)
now open u as sin2x
1/2 (( sin 2x^4)/4 - (sin 2x^6)/6)
1/2 (1/4- 1/6)
1/2 (1/12)
1/24

No need to thank me
because i didn't solve it
Rutzaba solved it for me

lawl u dint have to mention my name

 

[applepie1996]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_31.pdf

its question 9 .... problem is in the first few steps...... how come C = - 3 ? its coming 6 on myside (when doing the partial fractions) and finding A = 2 and B = 1 ?

applepie1996

or any one ? thanks alot

okay i think since the powers of the x's of the top half and the bottom half of the equations are the same you divide the two equations like how we do it in the polynomials chapter yeah then after you divide the two quadratic equation you get the quotient as "2" which will be A now to find B and C you have to factorize the bottom half of the equation which i am hoping you know how to do so the factors are (2x+1) and (x+2) sooooooo.......
now A + B/2x+1 + C/x+2 = 4x^2+5x+3 and you know A is 2 so find B and C . (which i am assuming you can do )

 

[applepie1996]

lawl u dint have to mention my name

nahhhh its fine
i didn't deserve the credit anyways
except maybe for the copy paste part

 

[applepie1996]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_31.pdf

its question 9 .... problem is in the first few steps...... how come C = - 3 ? its coming 6 on myside (when doing the partial fractions) and finding A = 2 and B = 1 ?

applepie1996

or any one ? thanks alot

if you don't get it tell me okay ??

 

[Rutzaba]

nahhhh its fine
i didn't deserve the credit anyways
except maybe for the copy paste part

oh come on u desrve equal amount of credit for the intention of helping^_^

 

[Silent Hunter]

now A + B/2x+1 + C/x+2 = 4x^2+5x+3 and you know A is 2 so find B and C . (which i am assuming you can do )

yeah i can ..... thats where am confused ..... can you please kindly find B in Bx+ C .... cua its here where the problem comes...... i get 3 while answr is 6 i think

and yeah ! thanks alot

 

[applepie1996]

yeah i can ..... thats where am confused ..... can you please kindly find B in Bx+ C .... cua its here where the problem comes...... i get 3 while answr is 6 i think

and yeah ! thanks alot

okiee
wait okay

 

[applepie1996]

oh come on u desrve equal amount of credit for the intention of helping^_^

awwww thanks

 

[Rutzaba]

wan me to solve it? or are you doing it apple?

 

[applepie1996]

yeah i can ..... thats where am confused ..... can you please kindly find B in Bx+ C .... cua its here where the problem comes...... i get 3 while answr is 6 i think

and yeah ! thanks alot

okay sooooo
its A + B/2x+1 + C/x+2=4x^2 + 5x + 3
and A is 2
so its 2(x+2) + B(x+2) +C(2x+1)=4x^2 + 5x + 3
first take x as -2 so B is zero and find C
then take as -1/2 so C is zero and find B

 

[applepie1996]

wan me to solve it? or are you doing it apple?

nah its fine
i did it
i would appreciate it if you helped me with a question
if you don't mind

 

[Rutzaba]

nah its fine
i did it
i would appreciate it if you helped me with a question
if you don't mind

pure math? bolo will if i cn

 

[applepie1996]

y

pure math? bolo will if i cn

yeap its pure
i just hate ....hate this chapter -_-
i never get the answer

 

[applepie1996]

yeah i can ..... thats where am confused ..... can you please kindly find B in Bx+ C .... cua its here where the problem comes...... i get 3 while answr is 6 i think

and yeah ! thanks alot

you got it or you want me to finish the whole thing