## agillogly Group Title write (cos pi/4+ i sin pi/4)^3 in trigonometric form 2 years ago 2 years ago

1. satellite73 Group Title

multiply the angle by three

2. satellite73 Group Title

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

3. satellite73 Group Title

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

4. agillogly Group Title

thanks.

5. satellite73 Group Title

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

6. satellite73 Group Title

yw