Question

write (cos pi/4+ i sin pi/4)^3 in trigonometric form

Answer 1

multiply the angle by three

Answer 2

\[\cos(\frac{3\pi}{4})+i\sin(\frac{3\pi}{4})\]

Answer 3

you also have to cube the modulus, but since it is one you just get one, so you can ignore that part
now if you want to write this in standard form as \(a+bi\) evaluate the functions and see what you get

Answer 4

thanks.

Answer 5

\[(\cos(\theta)+i\sin(\theta))^n=\cos(n\theta)+i\sin(n\theta)\] that is what makes this so easy

Answer 6

yw