Question

Determine the projection of the vector v = (−1, 6, 4) onto the vector u = (−1, 2, 4).

Answer 1

Projection is the dot product (if you have the angle), or in component format

projection- (-1*-1)+(6*2)+(4*4)
= 1+12+16=29

Answer 2

Yeah I understand that part, but what about projection onto vector u?

Answer 3

to project v onto u, just do

v • u/|u|
= 29/√21

If you want that in vector form, just multiply

29 * u/√21 = (-29/√21,58/√21,116/√21)