[wanderlust.xx]

Need 90% in C3. Well, that's my aim, and I think I can do it - Just one problem.

I get chapters 1-5 (edexcel), they're extremely easy and I've no doubt I can get 100% on any questions that arise from those chapters, but trigonometry and Differentiation are pretty hard, and I'm not sure about how to go and tackle revision on these subjects... I've got a mock exam in like December but my main aim is to be able to do all the Solomon papers by then... anyone have any general tips/advice?

Thanks!

[yusufu]

do questions, more questions and even more questions.

[wizz_kid]

Originally Posted by wanderlust.xx

Need 90% in C3. Well, that's my aim, and I think I can do it - Just one problem.

I get chapters 1-5 (edexcel), they're extremely easy and I've no doubt I can get 100% on any questions that arise from those chapters, but trigonometry and Differentiation are pretty hard, and I'm not sure about how to go and tackle revision on these subjects... I've got a mock exam in like December but my main aim is to be able to do all the Solomon papers by then... anyone have any general tips/advice?

Thanks!

There is always 1 and only 1 tip in maths in general. Practise as much as u can!

[Jsk]

Everyone has said it already, just practice. There is no easy way of learning maths. Why dont you try solomon papers, if you cant get them from school/college im sure i can send them to you. I would start off with just the questions you are finding difficult and start by using your notes and then start to get rid of your notes and they get easier.

You could also try and learn all the rules for differentiation .... my teacher send me a sheet with everything about differntiation that i needed to know. Also try and tearn the trig identities. You cant do trig without them. Maybe write some revision cards

[LeeC]

C3 Differentiation is very easy if you know these 3 rules and when to use them (here I have inlcuded how I know them but you might want to learn them a bit more formally):
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CHAIN RULE: For when you have a function of x to the power of something, eg (sinx)^2 usually written sin^2x ('sin squared x').

"Bring the power down, multiply by f(x), then multiply by f'(x)"

Eg. Differentiate y=(sinx)^2

Bringing the power down gives you 2 at the front, then f(x)=sinx and f'(x)=cosx.....

dy/dx= 2.sinx.cosx
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PRODUCT RULE: When you have two functions of x multiplied by eachother.

"First times the differential of the second + the second times the differential of the first"

Eg. Differentiate y=sinx.sinx

dy/dx=sinx.cosx + sinx.cosx = 2.sinx.cosx

Which also agrees with our result above using the chain rule. (sinx.sinx=sin^2x)
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QUOTIENT RULE: When you have a function of x divided by another function of x.

"Bottom multiplied by the differential of the top - Top times the differential of the bottom ALL divided by the bottom squared. you may want to check this, I can't be bothered lol, it should be easy to check by doing a question.

Eg. Differentiate y=sinx/ (x^2+3x)

dy/dx={(x^2+3x).cosx - sinx.(2x+3)}/ {(x^2+3x)^2}

=(x+3)(x.cosx-2.sinx)/(x^4+6x^3+9x^2)
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Then if you get a really nasty question like

Find f'(x) where f(x)= x^2.e^2x.sin^2x/cos^3x

You can use a combination of the rules.

Eg Treat e^2x.sin^2x as a seperte part and work out the derviative of that using the product rule...then multiply it by x^2 and use the product rule on that expression. Then use the product rule on cos^3x knowing that cos^3x=cos^2x.cosx (use the product rule again on cos^2 as above to get the derivative of that). Then once you have the derivatives of the top and bottom use the quotient rule on the whole lot.

I.e break it up like so:

{x^2.[e^2x.sinx]}/{cos.x.[cos^2x]}

Hope this is clear, any problems just PM me!