The angle at which the line, $\frac{x-1}{0}=\frac{2-y}{-1}=\frac{2z-3}{-2}$ is inclined with the positive direction of z-axis is |
$\frac{\pi}{4}$ $\frac{\pi}{2}$ $\frac{2\pi}{3}$ $\frac{3\pi}{4}$ |
$\frac{3\pi}{4}$ |
$\frac{x-1}{0} = \frac{2-y}{-1} = \frac{2z-3}{-2} = \lambda$ $x = 1$ $2 - y = -\lambda \Rightarrow y = 2 + \lambda$ $2z - 3 = -2\lambda \Rightarrow z = \frac{3}{2} - \lambda$ $\text{Direction ratios} = (0,1,-1)$ $\text{Direction cosines: } l = 0,\; m = \frac{1}{\sqrt{2}},\; n = \frac{-1}{\sqrt{2}}$ $\cos\theta = n = \frac{-1}{\sqrt{2}}$ $\theta = \cos^{-1}\left(\frac{-1}{\sqrt{2}}\right) = \frac{3\pi}{4}$ Final Answer: $\frac{3\pi}{4}$ |