The annual revenue of a small store in thousands of dollars is given by r(t) - 645 + 21t where t is the year, with t-0 corresponding to 2000. Similarity the stores annual profit is given by p(t) = 175+16t-0.3r^2
A) wrote a formula for the annual cost function C(t) for the store
B) compute C(3) and interpret your result in this context

Question

The annual revenue of a small store in thousands of dollars is given by r(t) - 645 + 21t where t is the year, with t-0 corresponding to 2000. Similarity the stores annual profit is given by p(t) = 175+16t-0.3r^2
A) wrote a formula for the annual cost function C(t) for the store 
B) compute C(3) and interpret your result in this context

jdoe0001 · Answer

well,, Cost = Revenue - Profit
thus
          C(x) = r(x) - p(x)

jdoe0001 · Answer

you bought 10 tomatoes for $5
you sell them for $1 each
you sell all 10, you make $10 total  <---- Revenue

the revenue is what get from the sale price
the sale price has, your cost and profit

you spend $5 for the tomatoes, $5 is the cost
revenue of $10 - $5 = profit
profit is $5

or
revenue - profit = cost, $10 - $5 = $5


on that case, you cost was $5, how much you paid for the tomatoes
and $5 for profit, how much you made from the work of selling them