Explain why an overdamped system never passes through the static equilibrium position when it is given

$($a$)$ an initial displacement only and $($b$)$ an initial velocity only.

Hint: determine the displacement response for the specific case $($a$)$ or $($b$)$ and then prove that u$($t$)$ will not

change sign. Also, think about the mathematical definition of cosh and sinh$.$