$\begin{array}{1 1}(a)\;\sqrt{\large\frac{x^2+1}{x^2+2}}&(b)\;\sqrt{\large\frac{x^2-1}{x^2+2}}\\(c)\;\sqrt{\large\frac{x^2+2}{x^2+1}}&(d)\;\large\frac{x^2+1}{x^2+2}\end{array}$
