Explanation

(c)
Line perpendicular to the given line $\frac{x}{a} - \frac{y}{b} = 1\ is$
$\frac{1}{b}x + \frac{1}{a}y + \lambda = 0$ …(i)
According to the question, line (i) is
Passing through the point $P(a,\ 0)$
[image:10_image44.emf]
$\therefore\frac{a}{b} + 0 + \lambda = 0$
$\Rightarrow \ \lambda = - \frac{a}{b}$
On putting the value of $\lambda\$ in Eq. (i), we get
$\frac{x}{b} + \frac{y}{a} - \frac{a}{b} = 0$
$\Rightarrow ax + by = a^{2}$