The polynomial 0.0013x^3-1.7x+12 models natural gas consumption in trillion
cubic ft. where x=0 corresponds to 1960, x=1 to 1961, and so on. In which year
between 1970 and 1990 was natural gas consumption about 17.3 trillion cubic ft.

Question

The polynomial 0.0013x^3-1.7x+12 models natural gas consumption in trillion
cubic ft.  where x=0 corresponds to 1960, x=1 to 1961, and so on.  In which year 
between 1970 and 1990 was natural gas consumption about 17.3 trillion cubic ft.

anonymous · Answer

based on what you have written, you need to solve

0.0013x^3-1.7x+12 = 17.3

anonymous · Answer

0.0013x^3-1.7x - 5.3 = 0
13x^3 - 17000x - 53000 = 0

anonymous · Answer

perhaps you can use your calculator to solve this cubic equation