Home › CBSE Class 12 (Commerce) › Mathematics › Three Dimensional Geometry › Lines with direction ratios 3, 5, 4 and 1, 1, 2 …
Lines with direction ratios 3, 5, 4 and 1, 1, 2 meet at an angle whose cosine is:
A8/15
B4√3/15
C8√3/15
D16/15
Answer & Solution
Correct answer: C. 8√3/15
The dot product is 16, and the magnitudes are 5√2 and √6, so cos θ = 16/(10√3) = 8√3/15.
Related questions
A line with direction ratios (1, 2, 2) is perpendicular to the line with ratios:Parametric equations x = 1 + 2λ, y = 3 - λ, z = 4λ give direction ratios:The line r = (2i - j + 4k) + λ(i + 2j - k) has direction ratios:How many straight lines pass through two distinct points in space?What is the length of the segment from P(-2, 4, -5) to Q(1, 2, 3)?Lines through two disjoint pairs of four non coplanar points are:A unit vector along the common perpendicular of lines with directions b1, b2 is:If (b1 x b2) . (a2 - a1) = 0 for two lines, the lines are: