The discussion focuses on simplifying the radical expression sqrt[1 - [(x-1)²/(x+1)²]]. A suggested method involves substituting 1 with (x+1)²/(x+1)², leading to the expression [(x+1)² - (x-1)²]/(x+1)². After expanding and combining the polynomial expressions in the numerator, the simplification results in sqrt[(4x)/(x+1)²]. The final simplified form is 2 * sqrt(x)/(x+1), demonstrating an effective approach to radical simplification.