Question

The equation of the line perpendicular to the line $\frac { x } { a } - \frac { y } { b } = 1$ and passing through the point at which it cuts x–axis, is.

• A. $\frac { x } { a } + \frac { y } { b } + \frac { a } { b } = 0$
• B. $\frac { x } { b } + \frac { y } { a } = \frac { b } { a }$
• C. $\frac { x } { b } + \frac { y } { a } = 0$
• D. $\frac { x } { b } + \frac { y } { a } = \frac { a } { b }$

Answer 1

Answer: (D)

$\frac { x } { b } + \frac { y } { a } = \frac { a } { b }$

Answer 2

The given line is $b x - a y = a b$

Obviously it cuts $x$ -axis at (a, 0). The equation of line perpendicular to (i) is $a x + b y = k$, but it passes through (a, 0) ⇒ $k = a ^ { 2 }$ .

Hence required equation of line is $a x + b y = a ^ { 2 }$

i.e., $\frac { x } { b } + \frac { y } { a } = \frac { a } { b }$ .