\(f\left(-x\right)=-x^3+\left(m^2-1\right)x^2-2x+m-1\)
Để hàm là hàm lẻ thì \(f\left(x\right)+f\left(-x\right)=0\) \(\forall x\)
\(\Leftrightarrow2\left(m^2-1\right)x^2+2m-2=0\) \(\forall x\)
\(\Leftrightarrow\left\{{}\begin{matrix}2\left(m^2-1\right)=0\\2m-2=0\end{matrix}\right.\) \(\Rightarrow m=1\)