How do you find the component form AND the magnitude of the vector v with initial point (1, 11) and terminal point (9, 3)?

Answer 1

the resultant vector is
(9-1 , 3-11) = (8,-8)
This is generally considered in component form

check with your textbook how they write the vector.
Some authors avoid the standard round brackets ( ..., ...) to avoid confusion with a point.
Some use this form [8,-8] others use <8 , -8> or some other variation.

the magnitude is √(8^2 + (-8)^2) = √128
= 8√2