Chapter 15: Problem 1464
The equation of the chord joining two points \(\left(\mathrm{x}_{1}, \mathrm{y}_{1}\right)\) and \(\left(\mathrm{x}_{2}, \mathrm{y}_{2}\right)\) on the rectangular hyperbola \(\mathrm{xy}=\mathrm{c}^{2}\) is (a) \(\left[x /\left(y_{1}+y_{2}\right)\right]-\left[y /\left(x_{1}+x_{2}\right)\right]=1\) (b) \(\left[x /\left(x_{1}-x_{2}\right)\right]+\left[y /\left(y_{1}-y_{2}\right)\right]=1\) (c) \(\left[x /\left(y_{1}-y_{2}\right)\right]-\left[y /\left(x_{1}-x_{2}\right)\right]=1\) (d) \(\left[\mathrm{x} /\left(\mathrm{x}_{1}+\mathrm{x}_{2}\right)\right]+\left[\mathrm{y} /\left(\mathrm{y}_{1}+\mathrm{y}_{2}\right)\right]=1\)