Energy The number of coal mines $C$ in the United States from 1980 to 2004 can be approximated by the equation $C=0.232 t^{3}-2.11 t^{2}-261.8 t+5699,$ for $0 \leq t \leq 24$ , where $t$ is the year, with $t=0$ corresponding to 1980 . (Source: U.S. Energy Information Administration)
(a) Use a graphing utility to graph the model over the domain.
(b) Find the number of mines in $1980 .$ Use the Remainder Theorem to find the number of mines in 1990 .
(c) Could you use this model to predict the number of coal mines in the United States in the future? Explain.