A) \[5\sqrt{3}\]
B) \[3\sqrt{5}\]
C) \[\frac{5}{\sqrt{3}}\]
D) \[\frac{5}{2}\]
Correct Answer: C
Solution :
[c] We have, \[\arg \left( \frac{z-4i}{z-3} \right)=\frac{\pi }{3}\] In \[\Delta OAB,\] \[\cos \frac{2\pi }{3}=\frac{O{{A}^{2}}+O{{B}^{2}}-A{{B}^{2}}}{2OA\cdot OB}\] \[\Rightarrow \] \[\frac{-1}{2}=\frac{2{{r}^{2}}-25}{2{{r}^{2}}}\]\[\Rightarrow \]\[3{{r}^{2}}=25\] \[r=\frac{5}{\sqrt{3}}\]You need to login to perform this action.
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