Answer
a. $6\ in$
b. $\frac{1}{2}\ Hz$
c. $2\ sec$
Work Step by Step
a. The maximum displacement equals to the amplitude of the oscillation, which can be found as $A=6\ in$
b. The frequency $f$ can be found with the relation $\omega=2\pi f=\pi$, which gives $f=\frac{1}{2}\ Hz$
c. The time required for one oscillation is the period which can be found as $T=\frac{1}{f}=2\ sec$
