Mathematics: Post your doubts here!

[iKhaled]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w12_qp_42.pdf

Q3.

Explanation as well please x)

okay the way i did this question is i used two equations then i used simultaneous equations

the equations i thought of and guessed they would help me are v = u +at and s = ut+1/2at^2....lets apply these equations to the motion through AB and BC

AB: V = u+at which is V= u+5a we also have 55= 5u + 12.5a

now lets take calculations for the motion from B to C....

BC: V2 = U2+5a and 65= 5U2+12.5a....now if u notice that U2 will be equal to V from because the final velocity of AB is the initial velocity of BC so U2= V(from the above equation)

65= 5(u+5a) +12.5a which is 65= 5u+37.5a...now u have two equations:

1. 55= 5u + 12.5a
2. 65= 5u+37.5a

use simultaneous equations and u will get a = 0.4 and u is 10...i hope u did get it now!

 

[littlecloud11]

Damn.. and here I thought my combination was difficult..

Further Maths, Bio, Chem, Physics, English.. one's mind would totally explode.. unless of course it's littlecloud11's mind

I've seen people with much crazier combinations.

 

[A star]

I've seen people with much crazier combinations.

a friend of mine has physics chem further maths accel maths accounts and eco in A2

 

[A star]

A star

your signature is wrong on so many levels.....

haha i know man i made it in middle of last year exams was tooooooo lazy to change

 

[littlecloud11]

a friend of mine has physics chem further maths accel maths accounts and eco in A2

Yup, qualified for the aforementioned group.

 

[syed1995]

a friend of mine has physics chem further maths accel maths accounts and eco in A2

Tell him.. he's crazy.. what field is he after? That combination would get him pretty much into anything except Medical.

imo. Pure sciences + Maths is the toughest combo..

 

[A star]

Tell him.. he's crazy.. what field is he after? That combination would get him pretty much into anything except Medical.

imo. Pure sciences + Maths is the toughest combo..

i dont know what he wants he took 14 or 15 subs in O levels and is on full exceptional scholarship. asked him the same thing he said opens up possibilities well eco is a choice since he is still in As

 

[A star]

Yup, qualified for the aforementioned group.

just supporting you as your comb seems normal with wacky combos i have seen

 

[ZainH]

okay the way i did this question is i used two equations then i used simultaneous equations

the equations i thought of and guessed they would help me are v = u +at and s = ut+1/2at^2....lets apply these equations to the motion through AB and BC

AB: V = u+at which is V= u+5a we also have 55= 5u + 12.5a

now lets take calculations for the motion from B to C....

BC: V2 = U2+5a and 65= 5U2+12.5a....now if u notice that U2 will be equal to V from because the final velocity of AB is the initial velocity of BC so U2= V(from the above equation)

65= 5(u+5a) +12.5a which is 65= 5u+37.5a...now u have two equations:

1. 55= 5u + 12.5a
2. 65= 5u+37.5a

use simultaneous equations and u will get a = 0.4 and u is 10...i hope u did get it now!

Oh wow thanks a ton , that helped

 

[syed1995]

i dont know what he wants he took 14 or 15 subs in O levels and is on full exceptional scholarship. asked him the same thing he said opens up possibilities well eco is a choice since he is still in As

Ah I see.. he's one of those.. Well I had only 8 subjects in O Levels. And I was happy with that! imo having too many subjects disrupts one's concentration.. If one's mind is focused that Yes I want to do engineering or Medical.. and he takes all relevant subjects.. then it makes sense..

But if one takes subject combination like Accounts, Biology, Chemistry, Computer, Sociology & Law or something similar.. I'd say the person's mind isn't set on what he wants to do in the future...

 

[iKhaled]

Oh wow thanks a ton , that helped

no problem. if u have anymore questions pls do ask and i will do my best to help!

 

[syed1995]

just supporting you as your comb seems normal with wacky combos i have seen

Oh I never that that the combination was crazy.. It is quite normal.. Pure sciences + Maths. I just said it was difficult.

 

[A star]

no i wasnt talking bout her combo just saying i have seen other combos which dont make sense like physics eco and acounts i mean whats the use of physics

 

[Rutzaba]

Oh I never that that the combination was crazy.. It is quite normal.. Pure sciences + Maths. I just said it was difficult.

no i wasnt talking bout her combo just saying i have seen other combos which dont make sense like physics eco and acounts i mean whats the use of physics

Yup, qualified for the aforementioned group.

sweet hearts ur convo is intercepting with the questions and there answers ... pleesh continue on ur wallls thankyee ^_^

 

[syed1995]

no i wasnt talking bout her combo just saying i have seen other combos which dont make sense like physics eco and acounts i mean whats the use of physics

Don't underestimate physics!

 

[syed1995]

sweet hearts ur convo is intercepting with the questions and there answers ... pleesh continue on ur wallls thankyee ^_^

Sowwie!

 

[Rutzaba]

Esme imma solve u the whole question but first i must tell you wat i am doing...
lets take a set of three variables that are a point on the line of which we have to find the equation...
a, b, c
then u know wat b1 is? its is substraction of one point from another on the line... suppose it is of coordinates i, j, k
then the equation of line would be sumthing like (a,b,c) +t (i, j, k) get this part...?
wat we have to do in this equation is to eliminate one variable either x or y or z and make one of them the subject of formula in terms of each variable... such as if we are making x as the subject of formula then... x in terms of x, in terms of y and in terms of z.
the general equation from wch we derive the equation of line is
(x-a)/i +(y-b)/j + (z-c)/k

 

[SalmanPakRocks]

No off-topics, please.

 

[Rutzaba]

No off-topics, please.

you just acted like punjab police! xD coming after the enemies have surrendered.... by the way chek inbox i solved ur q...

 

[Rutzaba]

Esme imma solve u the whole question but first i must tell you wat i am doing...
lets take a set of three variables that are a point on the line of which we have to find the equation...
a, b, c
then u know wat b1 is? its is substraction of one point from another on the line... suppose it is of coordinates i, j, k
then the equation of line would be sumthing like (a,b,c) +t (i, j, k) get this part...?
wat we have to do in this equation is to eliminate one variable either x or y or z and make one of them the subject of formula in terms of each variable... such as if we are making x as the subject of formula then... x in terms of x, in terms of y and in terms of z.
the general equation from wch we derive the equation of line is
(x-a)/i +(y-b)/j + (z-c)/k

further more

The two planes are x+2y-2z =2 ​

And 2x-3y +6z =3​

Lets say I like x and I want x to remain as it is and want y and z to converge to x.​

Now look at the two equations closely​

To eliminate y we can multiply the entire first equation by 3​

And the second eq by2 thus the both terms in y wud be plus six and minus six and wud be eliminated…​

The new eqs are 3x+ 6y- 6z=6​

And second wud be 4x – 6y +12z =6​

Y is eliminated….​

7x +6z=12​

7x= 12-6z ​

X =(12-6z)/7 …………… here is x in terms of z​

Now to eliminate the term in z we will take first eq multiply the it by 3. ​

And take the sec eq as it i.​

3x+ 6y -6z =6​

2x-3y +6z =3​

Z is eliminated we will get 5x+ 3y= 9​

X= (9-3y) /5 this is x in terms of y​

​

Now x=x in terms of y = x in terms of z​

(X-0)/1 + (9-3y)/5 = (12-6z) /7​

​

We re arrange… to make coefficient of y and z 1​

(X-0)/1 + -3 (y-3) /5 = -6 (z-2) /7 ​

(X-0)/1 +(y-3)/ (-5/3) = (z-2) /- 7/6​

By comparing this eqwuth the general formula we know that a=0 b=3 c=2​

And I=1 j= -5/3 and k=-7/6​

To simplify these points or to remove them from fractions you can multiply them with ---6… remember abc CANNOT be multiplied or divided but only b1 can be ie I j and k can be.​

We will get -6, 10 , 7​

Thus we have the eq of line​

(0, 3, 2) +t (-6, 10 , 7) J hope you get it​

​

Esme​