Incorrect. Recall that $\displaystyle{{a}}^{{3}}\usepackage{cmbright}\Huge\$ will have a negative value if $\displaystyle{a}<{0}\usepackage{cmbright}\Huge\$ . For example, $\displaystyle{{\left(-{2}\right)}}^{{3}}=-{2}\cdot-{2}\cdot-{2}=-{8}\usepackage{cmbright}\Huge\$ . What does this tell you about the truthfulness of the statement?