# Math Help - complex numbers

1. ## complex numbers

I know this isnt dealing with triangles but it is from my trig. class.
tried to figure tis problem out on my own but cant seem to get the right answer.

Find the indicated roots in the form a+bi.

the fourth roots of 16.

2. Originally Posted by mathdud
I know this isnt dealing with triangles but it is from my trig. class.
tried to figure tis problem out on my own but cant seem to get the right answer.

Find the indicated roots in the form a+bi.

the fourth roots of 16.

Note that $16=16\cdot 1=16\left(\cos 0+i\sin 0\right)$.
When you find the fourth roots, you need to simplify $\sqrt[4]{16}\left(\cos\!\left(\tfrac{2k\pi}{4}\right)+i\si n\!\left(\tfrac{2k \pi}{4}\right)\right)=2\left(\cos\!\left(\tfrac{k\ pi}{2}\right)+i\sin\!\left(\tfrac{k\pi}{2}\right)\ right)$ for $k=0,1,2,3$.