Anyone good at maths?! I'm stuck. evaluate in the form a + ib (with a and b real) e ^ (3-i[pi/3]) :cry: :cry: :cry: argh.

If I take my socks off I can just about count up to 18. Sorry, no help at all. Sure somebody will though. BMB xx

:wink: yeah! thanks though.... The assignment's due tomorrow and I've left it all too late again!! going to be a long night luce x

Okay it has been a while.. but here it goes... e ^ (3 - it) where t = pi / 3. can be expanded to (e^3) . (e^-it) as e ^ -it = cos(t) - i.sin(t) then the above can be written: (e^3) . (cos(t) - i.sin(t)) expanding and grouping: real part (a) = (e^3) . cos(pi / 3) imag part (ib) = -i . (e^3) . sin(pi/3) Could be totally wrong of course.. like I say it has been a while.. but if it helps, it helps

I see a new award category for the 48 months live awards this year, that of... "Most mind-boggling thread ':biggrin:

the "i" should not be included in the "imaginary part", I think. for a complaex number "a+ib", the imaginary part is "b" and of course sin(pi/3)=1/2 and cos(pi/3)=sqrt(3)/2 so real part = (e^3).sqrt(3)/2 and imag. part = -(e^3)/2 (I hope I didn't make any stupid mistakes )

haha my brain hurts now Laura!! Hopefully will make it along for a wee while on Saturday... will see if anyone else is going so I can scrounge a lift! Thanks to everyone for your help x x x

aww i remember the days when i didnt even know what imaginary numbers were... and now im preparing a presentation of the linear theory of waves. of course, i love maths, and i think laplace's equation is supercool! ROCK ON MATHS!!

I still don't know, but I've survived this far without needing too so I won't worry too much. Mind you, looking at my bank statement I think imaginary numbers are probably those without a minus sign in front of them. :-?

hmm i didnt think it was possible for bank accounts to go into plus numbers... im officially 62 quid past my overdraft limit. apparently thats bad (especially cos i need to pay that credit card bill... and i havent even bouhgt any new shoes for 5 months now)