C4 doubts

Scroll to see replies

Your integral should be

\displaystyle 4 \int_{\frac{\pi}{2}}^0 \sin^2 t \cos t \ dt

which does give 4/3

Note that x is the larger value when t=0.

is sin3x / 3 -sint right or worng? and how come the smaller value of 0 is on the top

Reply 21

Indeterminate

Original post by laurawoods

is sin3x / 3 -sint right or worng? and how come the smaller value of 0 is on the top

It's because it corresponds to the larger of the two values of x.

The integral evaluates to

\displaystyle -\frac{4}{3} \sin^3 t +C

Ignoring the +C, evaluating between 0 and pi over 2 gives the required answer.

Reply 22

yaboy

Original post by laurawoods

hello , i don't see how that could potentially work because if you diff 2x+3 you get just 2 , isn't it so? So it definitely cannot be forming that pattern of diff/ original function , isn't it so? Please correct me... :frown:

use substitution, let u= 2x+3 so 2x= u-3

Reply 23

laurawoods

Original post by Indeterminate

It's because it corresponds to the larger of the two values of x.

The integral evaluates to

\displaystyle -\frac{4}{3} \sin^3 t +C

Ignoring the +C, evaluating between 0 and pi over 2 gives the required answer.

Hello there ! how are you today? Do you have access to the MEI website , if u don't mind me asking?

Reply 24

Indeterminate

Original post by laurawoods

Hello there ! how are you today? Do you have access to the MEI website , if u don't mind me asking?

Fine, thanks :smile:

How do you mean?

Reply 25

laurawoods

Original post by Indeterminate

Fine, thanks :smile:

How do you mean?

Hello there, I just meant access to the website. I wanted to do practice from there to improve on these concepts....

Reply 26

laurawoods

Original post by Indeterminate

Fine, thanks :smile:

How do you mean?

Is the 'connected rates of change' and setting up simple diff equations pretty much the same idea? how are they similar and how r they different>

Reply 27

Indeterminate

Original post by laurawoods

Hello there, I just meant access to the website. I wanted to do practice from there to improve on these concepts....

Specifically, what are you after? Papers, revision sheets and stuff?

Reply 28

laurawoods

Original post by Indeterminate

Specifically, what are you after? Papers, revision sheets and stuff?

hello there , I am after some revision sheets specifically for C4? thanks :smile:

any help from ur side would be massively useful! I don't know if MEI and Integral Maths are the same or not?

(edited 11 years ago)

Reply 29

laurawoods

Original post by Indeterminate

Specifically, what are you after? Papers, revision sheets and stuff?

do you think you would be able to help me with the MEI i was requesting? thanks!

Reply 30

Indeterminate

Original post by laurawoods

do you think you would be able to help me with the MEI i was requesting? thanks!

Well, I've not found anything useful on the MEI website, but a quick google search took me to

http://www.london-oratory.org/maths/Solomon%20C4%20Worksheets/C4Edex/index.html

These questions tend to be harder than the Edexcel ones, so you should look to be able to tackle each question on each sheet for each topic. There are loads of sheets for vectors/integration.

Have fun! :smile:

(edited 11 years ago)

Reply 31

laurawoods

Original post by Indeterminate

Well, I've not found anything useful on the MEI website, but a quick google search took me to

http://www.london-oratory.org/maths/Solomon%20C4%20Worksheets/C4Edex/index.html

Have fun! :smile:

There is no fun in doing maths questions for me! :frown:

cool thanks! btw pls can you help me with this:

http://www.london-oratory.org/maths/Solomon%20C4%20Worksheets/C4Edex/pdf_files/E4Qdif_E.pdf

I was trying to do question 7b) but got a bit stuck ! do we have to solve diff equations to do that question or does this question come under the volume of revolution thing? thanks!

Reply 32

Indeterminate

Original post by laurawoods

There is no fun in doing maths questions for me! :frown:

Well, what's the volume after 5 seconds?

Once you've found that, you need to find h by rearranging and substitute to the V formula. Now, find

\dfrac{dV}{dh}

Hint:

\dfrac{dV}{dt} = \dfrac{dV}{dh} \times \dfrac{dh}{dt}

You're looking for dh/dt, which is the rate of change of the depth.

Reply 33

laurawoods

Original post by Indeterminate

Well, what's the volume after 5 seconds?

Once you've found that, you need to find h by rearranging and substitute to the V formula. Now, find

\dfrac{dV}{dh}

Hint:

\dfrac{dV}{dt} = \dfrac{dV}{dh} \times \dfrac{dh}{dt}

You're looking for dh/dt, which is the rate of change of the depth.

hello just a quick question out of interest , for oxbridge , so mathematicians have to do step exams or is it just an interview?

Reply 34

Mr M

Study Forum Helper

Original post by laurawoods

hello just a quick question out of interest , for oxbridge , so mathematicians have to do step exams or is it just an interview?

For Cambridge interview and two STEP papers.

For Oxford, entrance test and interview.

Reply 35

laurawoods

Original post by Mr M

For Cambridge interview and two STEP papers.

For Oxford, entrance test and interview.

ok cool ! if u don't mind me asking, did u get into oxbridge ? :smile:

Reply 36

Mr M

Study Forum Helper

Original post by laurawoods

ok cool ! if u don't mind me asking, did u get into oxbridge ? :smile:

I didn't try. I wanted to go to London (I had dreams of making it big in the music business) so attended UCL.

Reply 37

laurawoods

Original post by Mr M

I didn't try. I wanted to go to London (I had dreams of making it big in the music business) so attended UCL.

do u regret not applying to oxbridge? :smile:

Reply 38

laurawoods

Original post by Mr M

I didn't try. I wanted to go to London (I had dreams of making it big in the music business) so attended UCL.

Did u always want to be a Maths teacher or did u decide it later on in life? :smile:

Reply 39

Mr M

Study Forum Helper

Original post by laurawoods

do u regret not applying to oxbridge? :smile:

Well it hasn't made the slightest difference to my life at all. I did put Cambridge as my second choice for postgraduate teacher training but I was offered my first choice (the local provider) and this made sense as my children were settled in school.