Maths help

Irish Fox

i know I suck at maths.
can anyone help with these sums please ?

Differentiate the following with respect to x:

Sin 2x cos^2x

______________________

Find the slopes of the tangents to these curves at the given points:

y= (3x^2 - x -3)^5 at (1, - 1)

finality

Look, the second one is the same as the one I showed you the other day. The derivative is the slope, and you just use the line formula to get the tangent. You must use the chain rule here, multiply by the power and lower the power by 1, then multiply by the derivative of what's within the brackets.



I did this one out for you in detail, hopefully it'll help (and hopefully it's right, haha). You seem to be struggling with the chain rule, if this doesn't help you to get your head around it, you should think about asking your teacher to explain it to you. Unfortunately boards.ie won't be there during your leaving cert :P

Irish Fox

finality wrote: »

Look, the second one is the same as the one I showed you the other day. The derivative is the slope, and you just use the line formula to get the tangent. You must use the chain rule here, multiply by the power and lower the power by 1, then multiply by the derivative of what's within the brackets.



I did this one out for you in detail, hopefully it'll help (and hopefully it's right, haha). You seem to be struggling with the chain rule, if this doesn't help you to get your head around it, you should think about asking your teacher to explain it to you. Unfortunately boards.ie won't be there during your leaving cert :P

Chain I find is very difficult, this whole chapter is in fact
Thanks for your help after easter i will be able to drop to ordinary maths
so my nightmare will be over

Canard

Once you get your head around differentiation it all comes together - though I cant say much, struggling with rates of change :rolleyes:

Chain rule is basically just take the power, put it down front as usual, then derive whats in the brackets and multiply. Give HL a shot for a while anyway is my advice but of course its your choice :P

finality

I would marry calculus if I could... Good luck with it anyway, whichever level you end up doing

**Timbuk2**

With maths, it's really important to get the basics right if you wish to advance, and if you are struggling with the chain rule, you'll find a lot of the differentiation problems difficult, and even integration, if you haven't done that yet!

www.khanacademy.com is a great website for getting lots of maths lessons for free - you can also search khan academy on youtube, as all the videos are on youtube!

Go to the website and scroll down to calculus: I would recommend you watch the following videos, and hopefully they help!

https://www.youtube.com/watch?v=XIQ-KnsAsbg

https://www.youtube.com/watch?v=6_lmiPDedsY

https://www.youtube.com/watch?v=DYb-AN-lK94