Question

In the next questions, a particle is moving along a horizontal line according to the formula:
s=2t^4-4t^3+2t^2-1

a) the particle is moving right when
A. 0 is less than t is less than 1/2
B. t is greater than 0
C. t is greater than 1
D. 0 is less than t is less than 1/2, t is greater than 1
E. Never

b) the acceleration, a is increasing when
A. t is greater than 1
B. t is greater than 0.5
C. t is less than 0.211 or t is greater than .789
D. 0 is less than t is less than 0.5
E. 0 is less than t is less than 1

Answer 1

moving right when s is increasing. That is, when ds/dt > 0

a is increasing when da/dt is positive. That is,

48t-24 > 0
t > 2

Answer 2

t is greater than 0.5, not 2