Parametric differentiation : Edexcel Core Maths C4 June 2010 Q4(a) : ExamSolutions

[EdgefPain]

Thanks for all the help!

I did my C2, and S1 exams a few weeks ago. I think I may have got 100% in S1 and scraped an A in C2 (I got all the correct methods but made some errors)

I'm trying to get a head start in C3, C4, and M1, possibly FP1 and D1 for next year.

You've been a great help, I certainly will make a donation as soon as I have some money to do so.

[ExamSolutions_Maths]

Sounds that you are making good progress, well done. Any donation to help support my work is always gratefully received. Thanks

[ExamSolutions_Maths]

It would be silly to use it as you have a constant multiplied by a function of x. You would not use it to differentiate say 3x^2. It is just 3 multiplied by the differential of x^2.

[ExamSolutions_Maths]

It is easier to just differentiate it as it stands. Are you sure you are not getting confused though with integrating sin^2(x) which requires the use of the identity cos2x

[urbanvoices]

why do you not use the product rule when differentiating 2tant? surely it is 2 things multiplied by each other so you use f(x)g'(x)+f(x)g'(x)? thank you for your help.

[joewow]

when differentiating sin^2x why is the cos(2t) identity not used? Thanks

[Enigmo]

If I left the answer as cosectsec^3t would it still obtain full marks?

[MrSqilz]

why can you differentiate sin^2t using the cos2x identity?
i tried it but it didn't give the same answer in the mark scheme
(cos2x=1-2sin^2t)

[Xenos]

I understand that differentiating it as sin^2t is easier, but would I still get the marks for putting sec^2x/sin2t? As far as I can tell that still gives an accurate determination of dy/dx.

[tashicheerios]

Could you not simplify this fully to get just tan t on it's own?