Joanne sells silk screened T shirts at community festivals
     Joanne sells silk - screened T - shirts at community festivals and craft fairs.  Her marginal cost to produce one T - shirt is $2.50. Her total cost to produce 40 T - shirts is $150, and she sells them for $7 each.  Find the linear cost function for Joanne\'s T - shirt production.  How many T - shirts must she produce and sell in order to break even?.  How many T - shirts must she produce and sell to make a profit of $700?.  The linear cost function is C(x) =  (Type your answer in slope - intercept form.).  Joanne must produce and sell  T - shirts in order to break even.  Joanne must produce and sell  T - shirts to make a profit of $700. 
  
  Solution
dC/dx = 2.50 dC = 2.50dx integrating both the sides, C(x) = 2.50x + C1 for x = 40, C(x) = 150 C1 = 50 a.) C(x) = 2.50x + 50 b.) C(x) = S(x) 2.50x + 50 = 7x x = 11 units c) Profit = sold-cost 700 = 7x - 2.50x - 50 x = 167 units
