The demand function for the j-watch is given by the function.d(x)=8/(0.23x^2+1)  ,    0≤x ≤20.In this case x is the number of watches demanded weekly and d(x) is the price per unit in dollars. Determine the values d (5), d (10), d (15), and the values d '(5), d' (10), and d '(15). Interpret the meaning of d (10) and d '(10)