Suppose .
  1. Find the value of the expression in terms of the variable . (Enter the terms in the order given.)
    + + + help (formulas)

  2. Simplify your answer to the previous part and enter a differential equation in terms of the dependent variable satisfied by . Enter the derivatives of using prime notation ().
    = help (formulas)

  3. Is a solution to your differential equation in the previous part? Be sure you can justify your answer.

You can earn partial credit on this problem.