Question

If the distance covered by an object in time t is given by s(t) = 5t2 + t + 2, where s(t) is in meters and t is in seconds, what is the distance covered in the interval between 1 second and 4 seconds ?
72 meters
75 meters
78 meters
80 meters
81 meters

Answer 1

see how much it covers in 1sec

so you're asked to get the distance covered between 1 and 4 seconds

so get the distance covered in 4secs then and subtract the distance covered in 1sec

the difference will be the distance covered between 1 - 4 secs
\(\bf s({\color{brown}{ 4}}) -s({\color{brown}{ 1}})\)