9. The average velocity of a function, f, from t = a to t = b, is given by: \frac{1}{b-a} \int_{a}^{b} f(t) d t The velocity v(m/s) of a particle

at time t(s), is given by: v(t)=2 t+3 \sin (6 t)+\frac{4}{t} Determine the average velocity of the particle between t=1 and t=3.