ExamBro
ExamBro
AP EAMCET · Maths · Three Dimensional Geometry

If a line L makes angles \(\frac{\pi}{3}\) and \(\frac{\pi}{4}\) with Y -axis and Z -axis respectively, then the angle between L and another line having direction ratios \(1,1,1\) is

  1. A \(\cos ^{-1}\left(\frac{2}{\sqrt{6}}\right)\)
  2. B \(\cos ^{-1}\left(\frac{\sqrt{2}+1}{3 \sqrt{3}}\right)\)
  3. C \(\cos ^{-1}\left(\frac{\sqrt{2}-1}{3}\right)\)
  4. D \(\cos ^{-1}\left(\frac{\sqrt{2}+1}{\sqrt{6}}\right)\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(\cos ^{-1}\left(\frac{\sqrt{2}+1}{\sqrt{6}}\right)\)

Step-by-step Solution

Detailed explanation

L makes \(\frac{\pi}{3}\) and \(\frac{\pi}{4}\) angle with Y -axis and Z -axis \(\therefore m=\cos \frac{\pi}{3}=\frac{1}{2}\) and \(n=\cos \frac{\pi}{4}=\frac{1}{\sqrt{2}}\) and \(l^2+m^2+n^2=1 \Rightarrow l^2+\frac{1}{4}+\frac{1}{2}=1 \Rightarrow l=\frac{1}{2}\) Now, angle…