# Vector equations

## Homework Statement

What is the significance of each vector forumula? Which one is used for what and why? What is the purpose of the symmetric function?

## Homework Equations

1) r = r0 + tv
2) r(t) = (1 - t)r0 + tr1
3) Symmetric equation

## The Attempt at a Solution

My textbook introduced me to the first formula write equations for vectors, which I understand. Later it introduced segments and modified the first equation to the second one, without any clear explanation. I don't understand why seperate formulas are needed for vectors and segments. Finally, my textbook concluded that chapter by eliminating the parameter t and getting the "symmetric equation". What is the purpose of that equation? Thank you so much. This is so confusing for me.