Expression :Â $$\frac{\sqrt{2+x}+\sqrt{2-x}}{\sqrt{2+x}-\sqrt{2-x}}=2$$
=>Â $$\frac{\sqrt{2+x}+\sqrt{2-x}}{\sqrt{2+x}-\sqrt{2-x}} \times \frac{\sqrt{2+x}+\sqrt{2-x}}{\sqrt{2+x}+\sqrt{2-x}}=2$$
=> $$\frac{(\sqrt{2+x}+\sqrt{2-x})^2}{(\sqrt{2+x})^2-(\sqrt{2-x})^2}=2$$
=> $$\frac{(2+x)+(2-x)+2(\sqrt{2+x})(\sqrt{2-x})}{(2+x)-(2-x)}=2$$
=> $$\frac{4+2\sqrt{4-x^2}}{2x}=2$$
=> $$2+\sqrt{4-x^2}=2x$$
=> $$\sqrt{4-x^2}=2x-2$$
Squaring both sides, we get :Â
=> $$(\sqrt{4-x^2})^2=(2x-2)^2$$
=> $$4-x^2=4x^2+4-8x$$
=> $$5x^2-8x=0$$
=> $$x(5x-8)=0$$
=> $$x=\frac{8}{5}$$
=> Ans - (C)
Create a FREE account and get: