Question

If x cos y + y cos x = π, then y " (0) =

• A. 17
• B. –π
• C. 0
• D. 1

Answer 1

Answer: (A)

17

Answer 2

First differentiate w.r.t. X. Then without separating $\left( \frac{dy}{dx} \right)$, diff. again w.r.t. X and simultaneously put x = 0 and y = π