Answer:
1) Ben, 2) [tex]\Delta = 2[/tex], 3) [tex]\dot m = 2.7[/tex], 4) [tex]\dot M = 2.9[/tex]
Step-by-step explanation:
1) Ben has a higher rate of memorization, since the coefficient of the second power is lesser than the one from Alice.
2) The number of words can be estimated by integrating the function:
Alice
[tex]\Delta m = -0.003\cdot (10\,min)^{3} + 0.3\cdot (10\,min)^{2}[/tex]
[tex]\Delta m = 27[/tex]
Ben
[tex]\Delta M = -0.001\cdot (10\,min)^{3} + 0.3\cdot (10\,min)^{2}[/tex]
[tex]\Delta M = 29[/tex]
[tex]\Delta = \Delta M - \Delta m[/tex]
[tex]\Delta = 2[/tex]
3) The average amount of words per minute is:
[tex]\dot m = \frac{27}{10}[/tex]
[tex]\dot m = 2.7[/tex]
4) The average amount of words per minute is:
[tex]\dot M = \frac{29}{10}[/tex]
[tex]\dot M = 2.9[/tex]