Question

( vec{p}+vec{d}=vec{R} )
( Rightarrow quad vec{R}^{2}-vec{Q}^{2}=vec{p} )
( =R^{2}+Q^{2}-2 Q R cos theta=p^{2} )
( Rightarrow 13^{2}+12^{2}-2 times 13 times 12 cos theta=5^{2} )
( 759+144-25=312000 )
( cos theta=frac{288}{312}=frac{12}{13} )
( Rightarrow quad 0: cos ^{-1} frac{12}{13} )

# 55. (1) 0 (2) ~/3 (3) a) 2 1 4 04 If vectors P, and Ř have magnitudes 5, 12 and 13 units and P+ = Ř, the angle between Ő and Ř is : (1) cost (22) - (3) cos (13) (2) cost (33) (4) cosi (33)

Solution