A) \[4\]
B) \[8\]
C) \[16\]
D) \[2\]
Correct Answer: A
Solution :
Length of the chord \[=\sqrt{\begin{align} & {{[4\cos (\theta +{{60}^{o}})-4\cos \theta ]}^{2}} \\ & +{{[4\sin (\theta +{{60}^{o}})-4\sin \theta ]}^{2}} \\ \end{align}}\] \[=4\sqrt{\begin{align} & {{\cos }^{2}}(\theta +{{60}^{o}})+{{\cos }^{2}}\theta +{{\sin }^{2}}(\theta +{{60}^{o}}) \\ & +{{\sin }^{2}}\theta -2\cos (\theta +{{60}^{o}})\cos \theta \\ & -2\sin (\theta +{{60}^{o}})\sin \theta \\ \end{align}}\] \[=4\sqrt{1+1-2\cos \,{{60}^{o}}}=4\]
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