Question

Find the product. Express the result in rectangular form. 4(cos(pi/3 + isin(pi/3) * 7(cos(2pi/3) + isin(2pi/3)

Answer 1

multiply the numbers out front, add the angles
that is all

Answer 2

\[4\times 7=?\]
\[\frac{\pi}{3}+\frac{2\pi}{3}=?\]

Answer 3

28, pi

Answer 4

as mentioned => \(\bf r_1[cos(\alpha)+isin(\alpha)]\cdot r_2[cos(\beta)+isin(\beta)]
\\ \quad \\
\implies r_1\cdot r_2[cos(\alpha + \beta)+isin(\alpha + \beta)]\)

Answer 5

you got it

Answer 6

ok thnx cx

Answer 7

\[28(\cos(\pi)+i\sin(\pi))\]

Answer 8

it is ridiculously easy, which is pretty much the whole point of writing a complex number in trig form