A) 30
B) 28
C) 26
D) 24
Correct Answer: B
Solution :
If \[x=3-\sqrt{5}\] \[{{x}^{2}}=14-6\sqrt{5}\] And \[\frac{1}{{{x}^{2}}}=\frac{1}{14-6\sqrt{5}}\times \frac{14+6\sqrt{5}}{14+6\sqrt{5}}\] \[=\frac{14+6\sqrt{5}}{16}\] \[\frac{16}{{{x}^{2}}}=14+6\sqrt{5}\] Then, \[{{x}^{2}}+\frac{16}{{{x}^{2}}}=14-6\sqrt{5}+14+6\sqrt{5}\] \[=28\]You need to login to perform this action.
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