यदि वस्तु अपनी चली कुल दूरी की एक - तिहाई दूरी वेग `v_(1)` से दूसरी तिहाई दूरी वेग `v_(2)` से तथा शेष तिहाई दूरी वेग से चले तो उसका औसत वेग होगा :
`v_(av)=(S)/((S//3v_(1))+(S//3v_(2))+(S//3v_(3)))=(3v_(1)v_(2)v_(3))/(v_(1)v_(2)+v_(2)v_(3)+v_(3)v_(1))`

(9v + 1) + (3v + 1)

If |vec(V)_(1)+vec(V)_(2)|=|vec(V)_(1)-vec(V)_(2)|and V_(2) is finite, then

If |vec(V)_(1)+vec(V)_(2)|=|vec(V)_(1)-vec(V)_(2)|and V_(2) is finite, then

A car moves with speed v_(1) upto (t)/(3) time and then with speed v_(2) upto next (2t)/(3) time. Path is straight line.What is the average speed of car? " (A) (2v_(1)v_(2))/(v_(1)+v_(2)) (B) (v_(1)+v_(2))/(2) (C) (2v_(1)+v_(2))/(3) (D) (v_(1)+2v_(2))/(3)

Find 3 -dimensional vectors vec v_ (1), vec v_ (2), vec v_ (3) satisfying vec v_ (1) * vec v_ (1) = 4, vec v_ (1) * vec v_ (2) = - 2, vec v_ (1) * vec v_ (3) = 6, vec v_ (2) * vec v_ (2) = 2, vec v_ (2) * vec v_ (3) = - 5, vec v_ (3) * vec v_ (3)

If 1/(1+l)=v , prove that v+v^(2)+v^(3)+………+v^(n)=(1-v^(n))/l

Solve :3(2u+v)=7u v , 3(u+3v)=11 u v