From the trigonometrical identities, we know that
[tex]\cos 2x=\cos ^2x-\sin ^2x=2\cos ^2-1=1-2\sin ^2x[/tex]
These identites will give us cosine of 120 when x=60.
On the other hand,
[tex]\sin 2x=2\sin x\cos x[/tex]
which will give us sine of 120 when x=60.
Therefore, by comparing with the given options, the answer is:
[tex]2\sin 60\cos 60[/tex]
