Originally Posted by

**gidget** *This is exactly how the question reads from the book

Using the fact that a complex equation is really two real equations, find the double angle formulas (for Sin2$\displaystyle \theta\$, Cos2$\displaystyle \theta\$ ) by using this equation: (e^*i*$\displaystyle \theta\$)^*n* = (Cos$\displaystyle \theta\$+ *i*Sin$\displaystyle \theta\$)^*n* = Cos *n*$\displaystyle \theta\$ + *i*Sin *n*$\displaystyle \theta\$

I know if you put in 2 for n and just exapand it out I can get it but I figured that there might be some other way to prove it. Just seems a bit simple but any help or insight would be greatly appriciated.