Power and radical functions

2010014804

Level: 
C
Find the true statement about the function \( f(x)=\left|x^4-1\right| \).
The function \( f \) has the minima at \( x=-1 \) and \( x=1 \).
The function \( f \) has no minimum.
The function \( f \) has the minimum at \( x=0 \).
The function \( f \) has the minima at \( x=-1 \), \(x=0\) and \( x=1 \).