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

1. satellite73

multiply the angle by three

2. satellite73

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

3. satellite73

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

thanks.

5. satellite73

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

6. satellite73

yw

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