Mathematics · Straight lines

JEE Main 2024 — 31 January, Shift 2 — Question 2

Let A(a,b),B(3,4)\mathrm{A}(\mathrm{a}, \mathrm{b}), \mathrm{B}(3,4) and (−6,−8)(-6,-8) respectively denote the centroid, circumcentre and orthocentre of a triangle. Then, the distance of the point P(2a+3,7b+5)P(2 a+3,7 b+5) from the line 2x+3y−4=02 x+3 y-4=0 measured parallel to the line x−2y−1=0x-2 y-1=0 is

  1. Option A:

    1557\frac{15 \sqrt{5}}{7}

  2. Option B:

    1756\frac{17 \sqrt{5}}{6}

  3. Option C:

    1757\frac{17 \sqrt{5}}{7}

    Correct
  4. Option D:

    517\frac{\sqrt{5}}{17}

Answer: C

Step-by-step solution

A(a,b),B(3,4),C(−6,−8)\mathrm{A}(\mathrm{a}, \mathrm{b}), \mathrm{B}(3,4), \quad \mathrm{C}(-6,-8)

⇒a=0, b=0⇒P(3,5)\Rightarrow \mathrm{a}=0,\mathrm{~b}=0 \quad \Rightarrow \mathrm{P}(3,5)

Distance from P measured along x−2y−1=0\mathrm{x}-2 \mathrm{y}-1=0

⇒x=3+rcos⁡θ,y=5+rsin⁡θ\Rightarrow x=3+r \cos \theta, \quad y=5+r \sin \theta

Where tan⁡θ=12\tan \theta=\frac{1}{2}

r(2cos⁡θ+3sin⁡θ)=−17r(2 \cos \theta+3 \sin \theta)=-17

⇒r=∣−1757∣=1757\Rightarrow \mathrm{r}=\left|\frac{-17 \sqrt{5}}{7}\right|=\frac{17 \sqrt{5}}{7}

Solution figure

Answer key and solution verified before publishing.

Practise Straight lines

Start with this question, then two more from the same chapter — with a tutor that explains every step. Free.

Exam
JEE Main 2024
Subject
Mathematics
Chapter
Straight lines
Topic
Various forms of lines
Let A ( a , b ), B (3,4) and (-6,-8) respectively denote the… | JEE Main 2024 PYQ with Solution · DhiX AI