Question

A point moves in a straight line during the time t = 0 to t = 3 according to the law $s=15t-2t^2.$ The average velocity is
[MP PET 1992]

• A.
  3
• B. 9
• C. 15
• D. 27

Answer 1

The correct option is D 27

$I_n=\frac{d^{n-1}}{d{x}^{n-1}}[x^{n-1}+n{x}^{n-1}logx]$
$I_n=(n-1)!+n{I}_{n-1}\Rightarrow I_n-n{I}_{n-1}=(n-1)!.$