COMEDK2013MathematicsApplication of Derivatives
For the curve y^ n =a^ n-1 x if the subnormal at any point is a constant, then n is equal to
Options
- A1
- B2
- C-2
- D-1
Correct answer
B. 2
Step-by-step solution
We have, y^ n =a^ n-1 x n y^ n-1 d y d x =a^ n-1 y^ n-1 d y d x = 1 n a^ n-1 d y d x = 1 n a^ n-1 y^ 1-n Length of the subnormal = |y d y d x | = |y 1 n a^ n-1 y^ 1-n | = | 1 n a^ n-1 y^ 2-n | 2-n=0 n=2