Pure Mathematics 1.... AS students only

[axetreme.O]

discuss your doubts here guys..!!
http://www.twiddla.com/1174515

 

[L-Girl]

formula sheet, anyone?

 

[Lostsoul]

Some confusions in Integration and vextors.. when you intergrate it, you increase the power and divide it by the increased power, sometimes we have to multiply the first number of the Nominator also,, aswell as in integration. Help?

 

[oajisthebest]

Help please :'(

 

[hasan1234]

formula sheet, anyone?

https://forum.lowyat.net/topic/992396/all

 

[Manobilly]

Help please :'(
View attachment 24987

Both the questions are related to differentiation.In the 1st one we have been given dr/dt and he radius 50m. It is a circular patch and we have to find the rate at which the area of oil is increasing.Area of a circle is 3.142r^2.Differentiate it you will get 2pi*r.Substitute the value of r in 2pir. Than multiply it by 3 .
dA/dt=dA/dr *dr/dt

 

[Manobilly]

Help please :'(
View attachment 24987

In the 2nd question you need to 1st find the value of k.Substitute M with 3.2 and r with 10 to get k.
when you get k take differentiate the equation it will be 3kr^2. It is dM/dr .Multiply it the answer by dr/dt .You will get dM/dt

 

[L-Girl]

https://forum.lowyat.net/topic/992396/all

thank you so much

 

[Muhammad Arham Ayaz Malik]

Question7 O/N12 paper 11 ,part ii

Easy hy
For finding n first
Remember cos sq theota =1-sinsq theota
Apply it and make the equation
2sinsq ntheota + 3sin ntheota - 2 =0
Solve it quadratic
U get sinn theota =0.5. And =-2
Ignore -2 as it will give math error
Ok now when u solve for sin theotA=0.5 u get ntheota= (1st and 2n quad) 30,150
It says for the minimum POSITIVE value theota =10
Ntheota=30 , 10n=30 , n=3
This n will remain constant

Now the next part it says the largest value in 0-360
For sin 3theota find the values they will be
30,150,390,510,750,870 ( add 360 2 times as there will be three rotations as its 3 theota)
Now divide by 3 largest number in 360 range is 870/3=290

No likes needed just pray we all get straight a*

 

[Muhammad Arham Ayaz Malik]

Can anyone post the formula sheet?

This is the one u will be getting there probably
http://msnorsiah.files.wordpress.com/2012/01/formula-sheet.pdf

 

[Muhammad Arham Ayaz Malik]

Some confusions in Integration and vextors.. when you intergrate it, you increase the power and divide it by the increased power, sometimes we have to multiply the first number of the Nominator also,, aswell as in integration. Help?

When u differetiate for example 2(3x+3)^3
U multiply the power and reduce one and multiply the derivative in the brackets thats whys confusing u
In this it will be 6(3x+3)^2 multiply by 3

For integration of same
2(3x+3)^3
Increase power by one , divide it and multiply the derivate by denomatior!!
It will go like this
2(3x+3)^4 /4 multiply 3

I dont need likes pray we all get straight a*

 

[Muhammad Arham Ayaz Malik]

Help please :'(
View attachment 24987

First of all remember if A=bk ( k constant )
Then rate formula is
DA/DT = DB/DT multiply DB/DA
IN FIRST QUESTION FORMULA WILL BE A=pie r^2
Find DR/DA
2pie r =Da/dr
Now the formula for this is
Da/dt = dr/dt multiply dr/da
Radius increasing at 3 when initial is 50
Da/dt=3 x 2 pie (50)
=300 pie is answer


For second question apply the same with that formula find the value of k by putting values
M=kr^3
3.2=10^3k
K=o.oo32
If u dont get any part do let me know before the paper

 

[Muhammad Arham Ayaz Malik]

Anything else guys ??

 

[lightic]

Can u help me with this ? 9709_w12_qp_12

9) iii) Why cant you expand (2x+3)^2 first and then integrate the expanded terms. ALso on mark scheme says lower limit of zero can't be igonored, but why ?

11) i) Why Angle CRO is a right angle triangle?

Thx!

 

[Manobilly]

J

Easy hy
For finding n first
Remember cos sq theota =1-sinsq theota
Apply it and make the equation
2sinsq ntheota + 3sin ntheota - 2 =0
Solve it quadratic
U get sinn theota =0.5. And =-2
Ignore -2 as it will give math error
Ok now when u solve for sin theotA=0.5 u get ntheota= (1st and 2n quad) 30,150
It says for the minimum POSITIVE value theota =10
Ntheota=30 , 10n=30 , n=3
This n will remain constant

Now the next part it says the largest value in 0-360
For sin 3theota find the values they will be
30,150,390,510,750,870 ( add 360 2 times as there will be three rotations as its 3 theota)
Now divide by 3 largest number in 360 range is 870/3=290

No likes needed just pray we all get straight a*

JazakAllah

 

[Machikne]

Hey its easy bro just remember the concept of sin graph
the equation y=asin(bx)+c in every sin graph will mean
a=amplitude , in this case 9-3 =6
b=no of complete wave in 2pie (360 degrees) , in this case 2
c=the mean point where wave is starting , in this case 3
so it becomes
6sin2x+3=y


for the second part put y=0
u will get sin2 inverse = -0.5
ignore - and take sin in the opposite quadrants (2,3 )
now for sin2 inverse 0.5 u get 30
2nd quad
180-30=150

3rd quad
180+30=210

so you have two values 150,210 WAIT , remember it was sin2theota ? , divide it by 2
u get 75 and 105 least is 75 , thats ur answer if u dont understand ask me ,

bro isnt the 4 quadrant thing like this S | A
T | C

With S being taking Sin as positive, A as all being positive, C being cos postive and T being tan positive. SO when you worked out the quadrant, why did you use S and T - 180 + x (s) and 180 - X (t) . Shouldnt it be 180 + x (T) and 360 - x (C) since you get a negative value??

 

[oajisthebest]

Both the questions are related to differentiation.In the 1st one we have been given dr/dt and he radius 50m. It is a circular patch and we have to find the rate at which the area of oil is increasing.Area of a circle is 3.142r^2.Differentiate it you will get 2pi*r.Substitute the value of r in 2pir. Than multiply it by 3 .
dA/dt=dA/dr *dr/dt

First of all remember if A=bk ( k constant )
Then rate formula is
DA/DT = DB/DT multiply DB/DA
IN FIRST QUESTION FORMULA WILL BE A=pie r^2
Find DR/DA
2pie r =Da/dr
Now the formula for this is
Da/dt = dr/dt multiply dr/da
Radius increasing at 3 when initial is 50
Da/dt=3 x 2 pie (50)
=300 pie is answer


For second question apply the same with that formula find the value of k by putting values
M=kr^3
3.2=10^3k
K=o.oo32
If u dont get any part do let me know before the paper

Thanks

 

[Muhammad Arham Ayaz Malik]

bro isnt the 4 quadrant thing like this S | A
T | C

With S being taking Sin as positive, A as all being positive, C being cos postive and T being tan positive. SO when you worked out the quadrant, why did you use S and T - 180 + x (s) and 180 - X (t) . Shouldnt it be 180 + x (T) and 360 - x (C) since you get a negative value??

100% right , i mixed it with cosine , my bad
Answer same hy ittefak se

 

[Machikne]

100% right , i mixed it with cosine , my bad
Answer same hy ittefak se

same ?? how?

 

[Lostsoul]

I am doing variant two paper, so just solving variant 12 papers is enough?