C-11-Q133mediumsingle_mcqSolve 1−x1+x=12\sqrt{\dfrac{1-x}{1+x}} = \dfrac{1}{2}1+x1−x=21. Then x=x =x=a12\dfrac{1}{2}21b23\dfrac{2}{3}3ব্যাখ্যাSquaring gives 1−x1+x=14\dfrac{1-x}{1+x} = \dfrac{1}{4}1+x1−x=4, so . This yields , hence .