Algorithm Design

hello everybody...

I am new to this forum...Could u please help out in solving the following...


A complex number a+bi , where i=sqrt(-1) can be represented by the pair (a,b).Describe a method performing only three real-number multiplications to compute the pair (e,f) representing the product a+bi and c+di.


Please help me as soon as possible...

Thanks in anticipation

bye
chaitu

if dont' wanna use the regular way of multiplication:
(a+bi)(c+di) = ac - bd + i(ad+bc)
you could use the trigonometry way:
but i don't see how u could reduce the number of multiplications to 3.