Given : $$x=\frac{4}{2\sqrt{3}+3\sqrt{2}}$$
Rationalizing the denominator, we get :
=>Â $$x=\frac{4}{2\sqrt{3}+3\sqrt{2}}\times\frac{(2\sqrt3-3\sqrt2)}{(2\sqrt3-3\sqrt2)}$$
=> $$x=\frac{4(2\sqrt3-3\sqrt2)}{(12-18)}=\frac{2(3\sqrt2-2\sqrt3)}{3}$$ ---------(i)
Now, $$\frac{1}{x}=\frac{3}{2(3\sqrt2-2\sqrt3)}\times\frac{(3\sqrt2+2\sqrt3)}{(3\sqrt2+2\sqrt3)}$$
=> $$\frac{1}{x}=\frac{3(3\sqrt2+2\sqrt3)}{2(18-12)}$$
=> $$\frac{1}{x}=\frac{3\sqrt2+2\sqrt3}{4}$$ -------------(ii)
Adding equations (i) and (ii), we get :
=> $$x+\frac{1}{x}=(\frac{2(3\sqrt2-2\sqrt3)}{3})+(\frac{3\sqrt2+2\sqrt3}{4})$$
= $$\frac{8(3\sqrt2-2\sqrt3)+3(3\sqrt2+2\sqrt3)}{12}$$
= $$\frac{24\sqrt2-16\sqrt3+9\sqrt2+6\sqrt3}{12}$$
= $$\frac{33\sqrt2-10\sqrt3}{12}$$
=Â $$\frac{-(10\sqrt3-33\sqrt2)}{12}$$
=> Ans - (C)
Create a FREE account and get: