If A(3,4,5),B(4,6,3),C(-1,2,4)and D(1,0,5)are such that the angle between the lines DC and AB is θ, then cosθ is equal to
29
49
59
Explanation for correct option:
Direction ratios of DC are -1-1,0+2,4-5=-2,2,-1
Direction ratios of BA are 4-3,6-4,3-5=1,2,-2
As we know,
cosθ=a1a2+b1b2+c1c2a12+a22+a32b12+b22+b32=-2×1+2×2-1-24+4+11+4+4=49
Hence, Option ‘B’ is Correct.