(a)

The function is $\"\"$ .

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

$\"\"$

Find the differential of the function $\"\"$ , multiply both sides with $\"\"$ .

$\"\"$ .

(b)

$\"\"$ .

Find the value of the differential at $\"\"$ and $\"\"$ .

$\"\"$

(a) $\"\"$ .

(b) $\"\"$ .