What is the derivative of 5 cos^2 pi t?

1 Answer
Nov 15, 2016

= -10 pi cos(pi t) sin (pi t)

Explanation:

  1. hope you can read the notation :)
  2. deriv .. put in form 5 (cos ( pi t))^2
  3. power rule first gets 10 ( cos (pi t))
  4. chain rule requires that you multiply by the deriv of the inside function. d/dt ( cos ( pi t)) = - sin ( pi t) * pi
  5. the last multiply by pi is due to the chain rule applied to ( pi t)