The document discusses the derivatives of inverse trigonometric functions. It shows that if f and f-1 are inverse functions, their graphs are diagonally symmetric and the slopes of their tangent lines at corresponding points (a,b) and (b,a) are reciprocal. It derives formulas for the derivatives of the inverse trig functions arcsin, arccos, arctan, etc. using this property. It then gives examples of computing the derivatives of expressions involving inverse trig functions by applying the chain rule, using the derived formulas.