[i]The acceleration, a [math]ms^{-2}[/math], of a particle moving along a straight line at time[br]t seconds after passing a fixed point O is given by [math]a=12t-8[/math]. Given the particle's velocity, t = 1 second after passing O is –10 [math]ms^{-1}[/math]. Find the instantaneous displacement of the particle, in m, when[br][/i][br][i](a) its acceleration is 4 [math]ms^{-2}[/math][/i]

[i](b) the particle is at rest[/i]