First slide

Equation of line in Straight lines

Question

If non zero numbers a, b, c are in H.P, then the straightline $\frac{x}{a} + \frac{y}{b} + \frac{1}{c} = 0$ always passes through a fixed point. That point is

Moderate

A

$(1, - 2)$
B

$(1, - 1 / 2)$
C

$(- 1, 2)$
D

$(- 1, - 2)$

Solution

$a, b, c$ are in H.P
$\begin{array}{l} \Rightarrow \frac{1}{b} - \frac{1}{a} = \frac{1}{c} - \frac{1}{b} \\ \Rightarrow \frac{1}{a} - \frac{2}{b} + \frac{1}{c} = 0 \end{array}$
which shows that the given line passes through the point $(1, - 2) .$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App