(Solved): A coal-burning electrical generating plant emits sulfur dioxide into the surrounding air, The conce ...

A coal-burning electrical generating plant emits sulfur dioxide into the surrounding air, The concentration \( C(x) \), in parts per million, is approximately given by the function \[ C(x)=\frac{0.4}{x^{2}} \] where \( x \) is the distance away from the plant in miles. The instantaneous rate of change of the sulfur diowide concentration (to four decmal places) 6 miles from the plant is \( x \) parts per million per mile.