Third proportional 'c' to 'x' and 'y' is y²/x. Here, c = (a-b)² / (a²-b²) = (a-b)(a-b) / [(a-b)(a+b)] = (a-b) / (a+b).
तृतीयानुपाती 'c' का सूत्र y²/x है। यहाँ, c = (a-b)² / (a²-b²) = (a-b)(a-b) / [(a-b)(a+b)] = (a-b) / (a+b)।