college algebra

Question

Suppose the​ velocity, v, of an object is given by v=2t2+5t−7​, where t is time in seconds.​ (Here t can be positive or​ negative.) Find the intervals where the velocity is negative.

A.

between

−2

sec and

7

sec

B.

less than or equal to

0.1

sec and more than or equal to

2

sec

C.

between

−3.5

sec and 1 sec

D.

less than

0.5

sec and more than

7

sec

Answer 1

v = (2t + 7)(t - 1)

v = 0 at t = -7/2 and 1

C.