The Straight Lines — Maths STD 11 Science — Question
CBSE BoardEnglish MediumSTD 11 ScienceMathsThe Straight Lines3 Marks
Question
What are the points on y-axis whose distance from the line $\frac{\text{x}}{3}+\frac{\text{y}}{4}=1$ is 4 units?
✓
Answer
Let the required point be (0, a)
Given, distnace of (0, a) from line 4x + 3y - 12 = 0 is 4units.
$\text{D}=\Big|\frac{\text{ax}_1+\text{by}+\text{c}}{\sqrt{\text{a}^2+\text{b}^2}}\Big|$
$4=\Big|\frac{4(0)+3(\text{a})-12}{\sqrt{4^2+3^2}}\Big|$
$4=\Big|\frac{-3\text{a}+12}{5}\Big|$
$\Rightarrow4=\frac{-3\text{a}+12}{5}$
$\Rightarrow-3\text{a}=20-12$
$\text{a}=-\frac{8}{3}$
And $4=\frac{3\text{a}-12}{5}$
$\Rightarrow3\text{a}=20+12$
$\Rightarrow\text{a}=\frac{32}{3}$
So, Required points are
$\Big(0,\frac{32}{3}\Big),\Big(0,\frac{-8}{3}\Big)$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.