Question

Find the following product -5(cos pi/3 +isinpi/3)*2(cos pi/6+ isin pi/6'
I got 10i. is this correct?

Answer 1

cos PI/3= .5
sin PI/3= .866
cos PI/6=.866
sin PI/6=.5

put this into your google search engine
-5(.5+i*.866)*2*(.866+i*.5)=

Oh the magic of Google. Now warning, only use this to check your work

Answer 2

I got -10i

Did you get your answer by expanding
-10((cos pi/3 +isin pi/3)(cos pi/6+ isin pi/6) ?

my 2nd-last line was:
-10( cos π/2 + i sin π/2)