Question

Given, c=a-2b where a=4i+7j and b=-4i+j, find magnitude of c and the unit vector in the same position as c.

Answer 1

Given c=a-2b
a=4i+7j and b=-4i+j
As the terms are already in form of i and j, we can simply solve them to find the value of c
c=(4i+7j)-2(-4i+j)
c=12i-5j
Finding out the magnitude of c, we get
|c|=√[(12)^2+(5)^2]
|c|=13 units.
Unit vector in same position as c: vector/magnitude of vector.
=8i-6j/13