This app takes derivatives step-by-step, showing explanations in blue and highlighting in red the parts of the expression that have changed since the previous step. It is preloaded with the basic rules of differentiation including the constant rule, sum rule, product rule, quotient rule, chain rule, and power rule. It also knows the derivatives of trigonometric, inverse-trigonometric, exponential, square-root, and logarithmic functions. Finally, it is preloaded with close to 100 rules of algebraic simplification, which allow it to cancel-out or group common terms in expressions.