Find the angle formed when [3, 4] and [−5, 12] are placed tail-to-tail, then find components for the vector projection that results when [3, 4] is projected onto [−5, 12]

Answer 1

in your notes or in your textbook, I am sure you will find the following two formulas

for any two vectors a and b
1. a•b = |a||b|cosØ where Ø is the angle between them
2. The projection of a onto b is a•b/|b|

sub in the values and go for it.

Answer 2

Too bad. HA!