A company is manufacturing a new digital watch and can sell
     A company is manufacturing a new digital watch and can sell all it manufactures. The cost (in dollars) is given by C(x)=5,000 + 2x  where the production output in one day is x watches. If production is increasing at 5 watches per day when production is 375 watches per day, find the rate of increase in cost.  $75 per day  $10 per day  $5 per day  $175 per day 
  
  Solution
$75
