sir,

for expressing any complex number in its polar form,is it necessary to have a + sign between cos theta and isin theta???

yes,u hv 2 manage the angle lyk dat only so dat dere exists a + sign in betwn sine nd cosine f:ns......lets say a givn xpresion cos330^.-isin330^........here 330^. is d angle f 4th quad.....here cos is + n sine is(-)......also sine330^.can b written as (-)sin30^.and cos330^.is equal 2 cos 30^.only.....so expr cn b written as cis30^....!!similar concept cn b applied 2 odr problemz also.....as many ques u"ll practice.....ur confidence will boost up accordingly....ol d bes!!!!!