Mathematics: Post your doubts here!

[mominzahid]

Can someone please explain q7(i)?
http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w12_qp_42.pdf

 

[ZainH]

Nov 2012 .

Ah all right, so it's asking for the speed of the particle at O, which is where it starts to move from.
Obviously at this point the displacement will be 0, so we have to integrate the equation given for velocity and take it as 0.
This is because of the rule, which I'm assuming you know:

Displacement ---> Velocity ---> Acceleration (Differentiate)
Displacement <--- Velocity <--- Acceleration (Integrate)

Once you integrate it and take it as 0, you should get t = 80.
Now just put this value of t back into your equation for velocity, it should give you your speed.
Hope you got it x)

 

[GorgeousEyes]

Ah all right, so it's asking for the speed of the particle at O, which is where it starts to move from.
Obviously at this point the displacement will be 0, so we have to integrate the equation given for velocity and take it as 0.
This is because of the rule, which I'm assuming you know:

Displacement ---> Velocity ---> Acceleration (Differentiate)
Displacement <--- Velocity <--- Acceleration (Integrate)

Once you integrate it and take it as 0, you should get t = 80.
Now just put this value of t back into your equation for velocity, it should give you your speed.
Hope you got it x)

i got it Alhamdulelah , A big thanks

 

[GorgeousEyes]

GorgeousEyes there is no IV

what ?

 

[Esme]

Can someone please tell me how to do Q3 ........... Please
http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w10_qp_41.pdf

Phyzac solved this one for me. Here

 

[GorgeousEyes]

what paper do u recommend it to me to do it , as i don't have enough time .. a paper has a lot of ideas ?

 

[Esme]

what paper do u recommend it to me to do it , as i don't have enough time .. a paper has a lot of ideas ?

Any of the 2012 papers

 

[GorgeousEyes]

Any of the 2012 papers

Okay thank uu

 

[ZainH]

Can someone please explain q7(i)?
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w12_qp_42.pdf

It's given you the maximum velocity, at max velocity acceleration is 0.

So, since we have the equation for velocity , we need to change it to acceleration by differentiating it.
This gives us , 12ot-3t^2
We take this as 0 and find the value of t

120t-3t^2 = 0
3t(40t-4) = 0
t= 40

Now that we have a value of t , replace it in the original equation for velocity and take velocity as 6.4 since thats it's max.
k(60t^2-t^3) = 6.4
k(32000) = 6.4
k= 6.4/32000
k= 0.0002

Hope you get it x)

i got it Alhamdulelah , A big thanks

You're welcome.

 

[salvatore]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w10_qp_61.pdf
Could someone please explain qn no. 6 (iii, iv & v)? I don't understand what to do..
Thanks

 

[Pie-man]

we had this

This question rings a bell, which year ?
btw I think time should be t-2.

argument yesterday and it still is confusing why P has the t+2 instead of the Q

 

[Pie-man]

less than than 17 hours left for mechanics

 

[Esme]

less than than 17 hours left for mechanics

Are you worried ?

 

[Pie-man]

yeah cause i screwed up bad with pure and really hope mechanics gets me the A .... so no not at all

 

[Esme]

we had this
argument yesterday and it still is confusing why P has the t+2 instead of the Q

Well maybe you can get it if you imagine it happening in your head...

 

[haha101]

less than than 17 hours left for mechanics

Keep calm n hope no hard Q comes for M1

 

[Esme]

yeah cause i screwed up bad with pure and really hope mechanics gets me the A .... so no not at all

Oh! Well then I hope it goes well for you even though it has a lower weightage than P1..

 

[Esme]

Keep calm n hope no hard Q comes for M1

Haha insha'Allah

 

[Pie-man]

Keep calm n hope no hard Q comes for M1

yeah no hard questions at all

 

[Pie-man]

Oh! Well then I hope it goes well for you even though it has a lower weightage than P1..

thank you and btw i didn't screw it soo bad .. just screwed it so there might still be hope