A function $(t)$ satisfies the differential equation

$\frac{dy}{dt}=y^4-8y^{3}12y^2$

$($a$)$ What are the constant solutions of the equation? $($Enter your answers as a comma$-$separated list.$)$

$y=$

$$

$($b$)$ For what values of $y$ is $y$ increasing? $($Enter your answer in interval notation.$)$

yin

$$

$($c$)$ For what values of $y$ is $y$ decreasing? $($Enter your answer in interval notation.$)$

yin

$$