The equation is $\"\"$ .

(a)

$\"\"$ .

Differentiate on each side with respect to $\"\"$ .

$\"\"$

Substitute $\"\"$ , $\"\"$ and $\"\"$ in above expression.

$\"\"$

(b)

Consider $\"\"$ .

Substitute $\"\"$ , $\"\"$ and $\"\"$ in above expression.

$\"\"$

$\"\"$ .

(a) $\"\"$ .

(b) $\"\"$ .