(the vectors in the problem are really in column form, but i don't know how to type that so i put them in component form)
vectorP = 2i +5j
vectorQ = -i+ 2j
☆find the value of p·q
(I know the dot product is 8, that was ez) but the next part i don't get...
☆ if... s = kp - (p·q)q
find the value of the constant k such that s is perpendicular to q