Calculus help!

[Axionknight]

Not strictly science (or even at all), but I'm wondering if someone more learned than me can assist me here, with a calculus question I have on a paper, as part of my HNC.

I've gotten this one wrong and I'm not quite sure where I've messed it up, any help given would be appreciated!

http://postimg.org/image/6two7d7ot/

Please forgive my terrible writing, this back to work malarky doesn't suit me!

Cheers,

- Harvey

[Axionknight]

I'm only an electrician by trade, argh!

[Axionknight]

Much appreciated, Sir!

[Axionknight]

I don't get all that I just want to get on with programming my PLC's and building/designing instrumentation and control circuits.

I'm terrible at maths and always have been, cheers for the assistance all!

[Axionknight]

I appreciate all your assistance!!