\(a,f\left(0\right)=0^3-0.3+2=2\)
\(f\left(1\right)=1^3-3.1+2=0\)
\(f\left(-1\right)=-1+3+2=4\)
\(b,f\left(x\right)=x^3-3x+2\)
\(f\left(x\right)=x^3-x-2x+2\)
\(f\left(x\right)=x\left(x^2-1\right)-2\left(x-1\right)\)
\(f\left(x\right)=\left(x-1\right)\left(x^2+x-2\right)\)
Vậy f(x) = 0 \(\Rightarrow x=1\)
Vậy nghiệm của f(x) là : 1
\(c,h\left(x\right)=f\left(x\right)+x=0+1=1>0\)