s=(4t+3)(t−2)s = (4t + 3)(t - 2)s=(4t+3)(t−2)
dsdt=(4t+3)(1)+(t−2)(4)\frac{ds}{dt} = (4t + 3)(1) + (t - 2)(4)dtds=(4t+3)(1)+(t−2)(4)
= 4t+3+4t−84t + 3 + 4t - 84t+3+4t−8
= 8t - 5
dsdt(t=5 secs)=8(5)−5\frac{ds}{dt} (t = 5\text{ secs}) = 8(5) - 5dtds(t=5 secs)=8(5)−5
= 40 - 5
= 35 units per sec
