Thread: vector sketching

i am trying to figure these out but my answer are marked wrong.
my teacher wont explain it to me.

according to my textbook the projvu= [ (u dot v)/(v dot v) ] times v

consider the vectors u and v shown below


a) sketch projuv
this would be the projection of v onto u

my answer was the red vector below



b) sketch u-projvu
i put this as the answer and the teacher said that it wasn't completely wrong but there's something missing



c) determine the exact value of (u-projvu) dotted with v. show work.
i have no idea what to do here. i know that the projection of u onto v = [ (u dot v)/(v dot v) ] times v
but i dont know what to do after that

Originally Posted by jean91890

[ (u dot v)/(v dot v) ] times v

It may make a little more sense if you write it like this:

Perhaps this: