Question

If the subtangent at any point on y = a^1–n xⁿ is of constant length, then the value of n is

• A. $\frac{1}{2}$
• B. 1
• C. 2
• D. –2

Answer 1

Answer: (A)

$\frac{1}{2}$

Answer 2

$\frac{dy}{dx}$= a^1–nnx^n–1Ž sub tangent =y$\frac{dy}{dx}$= (a^1–n)² nx^2n–1

For constant length 2n – 1 = 0