A) \[\sqrt{32}\]
B) \[\sqrt{49}\]
C) \[\sqrt{140}\]
D) None of these
Correct Answer: A
Solution :
(a)\[6=a+\frac{1}{a}={{\left( \sqrt{a} \right)}^{2}}-2+{{\left( \frac{1}{\sqrt{a}} \right)}^{2}}+2\] \[={{\left( \sqrt{a}-\frac{1}{\sqrt{a}} \right)}^{2}}+2\] \[\therefore \,\,{{\left( \sqrt{a}-\frac{1}{\sqrt{a}} \right)}^{2}}=4\] Now \[\left( a-\frac{1}{a} \right)={{\left( \sqrt{a} \right)}^{2}}+2+{{\left( \frac{1}{\sqrt{a}} \right)}^{2}}\]
You need to login to perform this action.
You will be redirected in
3 sec
