The position vectors of points A,B,C and D are A=3^i+4^j+5^k,B=4^i+5^j+6^k, C=7^i+9^j+3^k and D=4^i+6^j. Then, the displacement vectors AB and CD are
A
perpendicular
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
parallel
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
antiparallel
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
inclined at an angle of 60∘
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is C antiparallel We know, −−→AB=→B−→A −−→AB=(4^i+5^j+6^k)−(3^i+4^j+5^k) −−→AB=^i+^j+^k
Similarly, −−→CD=→D−→C −−→CD=(4^i+6^j)−(7^i+9^j+3^k) −−→CD=−3^i−3^j−3^k
So we can write, −−→CD=−3(−−→AB). ∴ Vectors AB and CD are antiparallel