$\"\"$

The dot product of $\"\"$ and $\"\"$ is $\"\"$ .

The vectors $\"\"$ and $\"\"$ are orthogonal if and only if $\"\"$ .

$\"\"$

The vectors are $\"\"$ and $\"\"$ .

$\"\"$

Since $\"\"$ , the vectors $\"\"$ and $\"\"$ are orthogonal. $\"\"$

$\"\"$ ; orthogonal.