How should i prove this equation on determinant?
How do I prove [math]\omega_1\cdot\omega_2\cdot\omega_3\cdot\omega_4\cdot\omega_5=1[/math] where [math]\omega_k=\cos\frac{2\pi(k-1)}5+i\sin\frac{2\pi(k-1)}5[/math] ?