a. v(t)=11+t2v\left( t \right) = {1 \over {1 + {t^2}}}v(t)=1+t21
b. $$$a\left( t \right) = {{ - 2t} \over {{{\left( {1 + {t^2}} \right)}^2}}}$$$
c. (a) 0.20.20.2, 0.060.060.06, 0.030.030.03 (b) −0.16-0.16−0.16, −0.028-0.028−0.028, −0.0088-0.0088−0.0088
d. El disco de hockey está desacelerando a los 2, 4 y 6 segundos