# complex number polar form

• February 23rd 2009, 10:00 AM
alpharebel10
complex number polar form
convert the complex number -8+5i into the form re^itheta
does it mean the same as polar form so i will get
9.4<2.59
so 9.4cos 2.59 +9.4 sin 2.59 =-8+5i
or is it asking for something else any help would be very greatful
also i have a couple of these and also dont understand
evaluate;
3e^2i
e^iPi
and a couple more with basically the same things but dont know what to do thank you for any help cheers
• February 23rd 2009, 10:26 AM
Plato
$r = \sqrt {64 + 25} \;\& \,\theta = \arctan \left( {\frac{5}
{{ - 8}}} \right) + \pi$