Write the Word or Phrase That Best Completes Each Statement $\mathrm { P }$

Essay

Write the word or phrase that best completes each statement or answers the question.
-A mass hangs from a spring which oscillates up and down. The position $\mathrm { P }$ (in feet) of the mass at time $t$ (in secon given by
$$P = 4 \cos ( 4 \mathrm { t } )$$
For what values of $t , 0 \leq t < \pi$ , will the position be $2 \sqrt { 2 }$ feet? Find the exact values. Do not use a calculator.