Question

(6+6i)(-3+3i)
put in trigonometric form

Answer 1

before or after you multiply?

Answer 2

either way i guess.

Answer 3

if you multiply you get -36

Answer 4

which in trig form would be
\[36(\cos(\pi)+i\sin(\pi))\]

Answer 5

how did you get -36?

Answer 6

my guess is you are supposed to put them in trig form first

Answer 7

well no, you got the right answer, i just want to know how to do it

Answer 8

\[(a+bi)(c+di)=(ac-bd)+(ad+bc)i\] so
\[(6+6i)(-3+3i)=(-18-18)+(18-18)i=-36\]

Answer 9

trig form of \(6+6i\) is \(6\sqrt{2}(\cos(\frac{\pi}{4})+i\sin(\frac{\pi}{4}))\)

Answer 10

angle should be clear because you are over 6 and up 6, and \(r=\sqrt{6^2+6^2}=\sqrt{2\times 6^2}=6\sqrt{2}\)

Answer 11

similarly \(-3+3i=3\sqrt{2}(\cos(\frac{3\pi}{4})+i\sin(\frac{3\pi}{4}))\)

Answer 12

okay, i get it thank you(:

Answer 13

yw