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QJEEM22Ma65e1: JEE Main 2022 Mathematics - Class 12 JEEM22Ma65e1 Solution: Let and be two points on the line at a distance from the point…

Let Q\mathrm{Q} and R\mathrm{R} be two points on the line x+12=y+23=z−12\frac{x+1}{2}=\frac{y+2}{3}=\frac{z-1}{2} at a distance 26\sqrt{26} from the point P(4,2,7)P(4,2,7) . Then the square of the area of the triangle PQRP Q R is ___________.

Step-by-Step Verified Solution

L:x+12=y+23=2−12L:{{x + 1} \over 2} = {{y + 2} \over 3} = {{2 - 1} \over 2}

JEE Main 2022 (Online) 26th July Morning Shift Mathematics - 3D Geometry Question 148 English Explanation

Let T(2t−1, 3t−2, 2t+1)T(2t - 1,\,3t - 2,\,2t + 1)

∵\because PT ⊥r QRPT\,{ \bot ^r}\,QR

∴\therefore 2(2t−5)+3(3t−4)+2(2t−6)=02(2t - 5) + 3(3t - 4) + 2(2t - 6) = 0

17t=3417t = 34

∴\therefore t=2t = 2

So T(3,4,5)T(3,4,5)

∴\therefore PT=1+4+4=3PT = \sqrt {1 + 4 + 4} = 3

∴\therefore QT=26−9=17QT = \sqrt {26 - 9} = \sqrt {17}

∴\therefore Area of ΔPQR=12×217×3=317\Delta PQR = {1 \over 2} \times 2\sqrt {17} \times 3 = 3\sqrt {17}

∴\therefore Square of ar(ΔPQR)=153ar(\Delta PQR) = 153 .

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