Problem : What is the difference between a vector and a ray?

A vector has finite length, whereas a ray extends in one direction without limit.

Problem : A vector has origin at (1,2) and endpoint at (-3,-4). What is the horizontal, or x-component of this vector?

-4

Problem : How many vectors are needed to form the coordinate plane?

An infinite number. Vectors have finite length--therefore it requires an infinite number of vectors to form the coordinate plane, which extends in all directions without limit.

Problem : A vector has origin at (-3,5) and endpoint at (0,8). What is the magnitude of this vector?

= 3

Problem : . . What is 3?

(,)