busn calc revenue

Question

a manufacturer estimates that when x units of a certain commodity are produced and sold, the revenue derived will be R(x)=0.5x^2+3x-2 thousand dollars. at what rate is the revenue changing with respect to the level of production when 3 units are being produced? is the revenue increasing or decreasing at this time, why?

Answer 1

You need to take the derivative. Remember that the derivative of x^k is kx^k-1