Question 1098756
A particle moves along a line so that its position at any time t>=0 is given by s(t) = 2+7t-t^2

At which of the following times is the particle moving to the left?
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Speed = 1st derivative of position.
s(t) = 2+7t-t^2
s'(t) = 7 - 2t
Speed is decreasing when s'(t) < 0
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At t=4, speed = -1, which is "moving left" if left is defined as decreasing.
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Another poorly written problem.

A. t=0 B. t=1 C. t=2 D. t=7/2 E. t= 4