In the year 1993, the average cost of a radio could be modeled by the equation C = -15t2 + 1000 where t is the number of years since 1993. By the year 2006 the average cost had changed, so it could be modeled by the equation C = -5t2 + 1200. Find the difference in the average costs for a television between 2006 and 1993
I think:
\(C_{1993}-C_{2006}=-15\times 0^2+1000-(-5\times 0^2+1200)=-200\)
Answer: 200