$\"\"$

\

The function is $\"\"$ .

\

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

\

Find the value of $\"\"$ .

\

$\"\"$ .

\

Differentiation rule: $\"\"$ .

\

$\"\"$

\

Consider $\"\"$ .

\

Apply derivative on each side with respect to $\"\"$ .

\

$\"\"$

\

$\"\"$ .

\

$\"\"$ .

\

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

\

$\"\"$ .

\

$\"\"$

\

Find $\"\"$ .

\

$\"\"$

\

$\"\"$ .

\

Find $\"\"$ .

\

$\"\"$

\

$\"\"$ .

\

Substitute the above results in $\"\"$ .

\

$\"\"$

\

$\"\"$

\

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

\

$\"\"$

\

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