$\"\"$

Ryan $\"\"$ s answer is $\"\"$ .

Alicia $\"\"$ s answer is $\"\"$ .

Ryan $\"\"$ s answer is correct, when compared to Alicia $\"\"$ s answer.

$\"\"$

Proof :

The equation is $\"\"$ .

Differentiate with respect to $\"\"$ .

$\"\"$

$\"\"$ .

Apply the formula : $\"\"$ .

$\"\"$ .

$\"\"$ which matches with Ryan $\"\"$ s answer.

Therefore Ryan $\"\"$ s answer is correct and Alicia $\"\"$ s answer is wrong.

$\"\"$

Ryan $\"\"$ s answer is correct.