Question

What is the best approximation of the projection of (2,6) onto (5,-1)?

I guess onto (5, -1) leaves me with choices A. or C.

Answer 1

The projection of b onto a equation is : \[proj _{a}b= ((a.b)/|a|^{2})a \] , where a , and b are vectors.

Answer 2

But what choice is that?

Answer 3

you can derive the formula for the projection.
we know from the dot product formula
$$
\large \bf \vec {a} . \vec {b} = |a| |b| \cos \theta

$$