Equation of a line is $\frac{x-3}{2}=\frac{4-y}{3}=\frac{2-z}{4}$ then its direction cosines are : |
$2,3, 4$ $2, -3, -4$ $\frac{2}{29},\frac{-3}{29}, \frac{-4}{29}$ $\frac{2}{\sqrt{29}}, \frac{-3}{\sqrt{29}},\frac{-4}{\sqrt{29}}$ |
$\frac{2}{\sqrt{29}}, \frac{-3}{\sqrt{29}},\frac{-4}{\sqrt{29}}$ |
The correct answer is Option (4) → $\frac{2}{\sqrt{29}}, \frac{-3}{\sqrt{29}},\frac{-4}{\sqrt{29}}$ first converting eq. to std. form $\frac{x-3}{2}=\frac{4-y}{3}=\frac{2-z}{4}$ DR's = 2, -3, -4 DC's = $\frac{2}{\sqrt{2^2+(-3)^2+(-4)^2}},\frac{-3}{\sqrt{2^2+(-3)^2+(-4)^2}},\frac{-4}{\sqrt{2^2+(-3)^2+(-4)^2}}$ DC's = $\frac{2}{\sqrt{29}}, \frac{-3}{\sqrt{29}},\frac{-4}{\sqrt{29}}$ |