Question

Find the product of the complex numbers. Express your answer in trigonometric form.

z1=5(cos(25)+i sin(25)
z2=2(cos(80)+i sin(80)

Answer 1

I think its either A. or B.

Answer 2

hint:
\[\begin{gathered}
{z_1} = 5{e^{i25}} \hfill \\
{z_2} = 2{e^{i80}} \hfill \\
{z_1} \times {z_2} = 5 \times 2 \times {e^{i25}} \times {e^{i80}} = ...? \hfill \\
\end{gathered} \]

Answer 3

do I take 80-25=55
360-55= 305

is that how you solve this

Answer 4

\[{e^{i25}} \times {e^{i80}} = {e^{i\left( {25 + 80} \right)}} = {e^{i105}}\]

Answer 5

we have to sum 25 with 80

Answer 6

oh so b. 105 then

Answer 7

ok!

Answer 8

if you were looking for the quotient would you subtract

Answer 9

yes!