If and then at is equal to
Explanation for the correct option:
Step 1. Finding the value of at
Given, and
…..(1)
Replace by in equation (1)
…..(2)
Step 2. Multiplying equation (1) by and equation (2) by
…..(3)
…..(4)
Step 3. Subtracting equation (4) from equation (3),
…..(5)
Given that
Step 4. Substituting the value of in equation (5),
Step 5. Differentiating it with respect to
Put
Hence, Option ‘C’ is Correct.