Question

A particle's position is given by x = 4.0t^2 - 32t + 36, with x in meters and time t in seconds. At what position does the particle come to a momentary stop, to reverse its motion?

Answer 1

when it gets to zero or the intercept
factor
x=4(t^2-8t+9)
x=(4)(t-9)(t+1)
set to zero
t-9=0
t=9
t+1=0
t=-1, false, time cannot be negative


at t=9 seconds