$\"\"$

The vector is $\"\"$ .

The standard form of the vector is $\"\"$ .

Compare the vector with general form. \ \

$\"\"$ and $\"\"$ . \ \

The value of $\"\"$ is negative, hence the direction angle is $\"\"$ . \ \

Substitute $\"\"$ and $\"\"$ .

$\"\"$

$\"\"$ .

Direction angle is $\"\"$ .

$\"\"$

Direction angle is $\"\"$ .