Question 1202476
.
<pre>

The unit vector is the given vector divided by the modulus, which is another name
for the length of the vector.


The length of the given vector is  L = {{{sqrt(2^2 + (-4)^2)}}} = {{{sqrt(4 + 16)}}} = {{{sqrt(20)}}} = {{{2*sqrt(5)}}}.


Therefore, the unit vector in this problem is

    {{{v[unit]}}} = {{{(1/sqrt(5))}}}*i - {{{(2/sqrt(5))}}}*j,


which is the same as

    {{{v[unit]}}} = {{{sqrt(5)/5}}}*i - {{{(2*sqrt(5))/5}}}*j.
</pre>

Solved.