A) 4
B) 13/4
C) 17/4
D) 15/4
Correct Answer: D
Solution :
(d): \[a+\frac{1}{a}=\frac{17}{4}\] Squaring, \[{{a}^{2}}+2+\frac{1}{{{a}^{2}}}=\frac{289}{16}\] Subtracting '4', we get \[{{a}^{2}}-2+\frac{1}{{{a}^{2}}}=\frac{289-64}{16}\] \[\Rightarrow {{\left( a-\frac{1}{a} \right)}^{2}}={{\left( \frac{15}{4} \right)}^{2}}\,\,\,\,\,\Rightarrow a-\frac{1}{a}=\frac{15}{4}\].You need to login to perform this action.
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