Answer:
[tex]s'(t) = 21t^{2} - 2t[/tex]
The slope of the tangent line is 1683 at t=9.
Step-by-step explanation:
Given function s' = 7t³ - t²
[tex]s'(t) = (7 * 3)t^{3-1} - (2 * 1)t^{2-1}[/tex]
[tex]s'(t) = 21t^{2} - 2t[/tex]
The slope of the tangent line at t = 9
[tex]s'(t)|_{t=9} = 21(9)^{2} - 2(9)[/tex]
[tex]s'(t)|_{t=9} = (21 * 81) - 18[/tex]
[tex]s'(t)|_{t=9} = 1701 - 18[/tex]
[tex]s'(t)|_{t=9} = 1683[/tex]