| − | A power rule is any mathematical rule or shortcut that applies when there is a variable to a constant power. The most common example is the power rule of differentiation, <br> | + | A power rule is any mathematical rule or shortcut that applies when there is a variable to a constant power. The most common example is the power rule of differentiation, f'(x<sup>n</sup>)=nx<sup>n-1</sup> |