Science:Math Exam Resources/Courses/MATH200/December 2011/Question 02 (b)/Hint 1

You should use your answer from part (a) to solve this problem:

${\frac {\partial ^{2}z}{\partial t^{2}}}={\frac {\partial }{\partial t}}\left({\frac {\partial z}{\partial t}}\right).$