If \[x+\frac{1}{x}=2\,\cos \theta ,\] then \[{{x}^{3}}+\frac{1}{{{x}^{3}}}=\] [MP PET 2004]

If \[x+\frac{1}{x}=2\,\cos \theta ,\] then \[{{x}^{3}}+\frac{1}{{{x}^{

1.	If \[x+\frac{1}{x}=2\,\cos \theta ,\] then \[{{x}^{3}}+\frac{1}{{{x}^{3}}}=\] [MP PET 2004]
A.	\[\cos \,\,3\theta \]
B.	\[2\,\cos \,3\theta \]
C.	\[\frac{1}{2}\cos \,3\theta \]
D.	\[\frac{1}{3}\cos \,3\theta \]
Answer» C. \[\frac{1}{2}\cos \,3\theta \]