(a) If $y = \cos^{3}(\sec^{2} 2t)$, find $\frac{dy}{dt}$. OR (b) If $x^{y} = e^{x-y}$, prove that $\frac{dy}{dx} = \frac{\log x}{(1 + \log x)^{2}}$.

Year	Paper Code	Set	Position
CBSE 2024	Series Other	Set 1	Question 22
CBSE 2024	Series Other	Set 1	Question 24
CBSE 2024	Series Other	Set 1	Question 21

• Step 1: Stating the fundamental formula / law statement (+1 Mark)
• Step 2: Intermediate mathematical substitution or proof steps (+1 Mark)
• Step 3: Correct final value or conclusion with mandatory SI units (+1 Mark)