- Show that
cosθ=(u⋅v)/(|u||v|)
for 2D vectors u and v.
(it is quite hard to come up with these challenges, so if you got any ideas, please post them)
cosθ=(u⋅v)/(|u||v|)
for 2D vectors u and v.(it is quite hard to come up with these challenges, so if you got any ideas, please post them)
Making one additional note here, because of your parenthetical message, letting you know that my short backlog of problems I found interesting has actually run dry with the last one I posted - so my series is unfortunately on hiatus. I’ll still post if I come across other interesting problems but that honestly doesn’t happen too often - even the ones I have posted were collected (and saved by a friend) over several years.