posted by Mike .
The relationship between the amount of money x that Cannon Precision Instruments spends on advertising and the company's total sales S(x) is given by the following function where x is measured in thousands of dollars.
S(x) = -0.002x3 + 0.9x2 + 4x + 500 (0 x 200)
Find the rate of change of the sales with respect to the amount of money spent on advertising.
Are Cannon's total sales increasing at a faster rate when the amount of money spent on advertising is $100,000 or $150,000?