Question

An equation of a function y(t) is shown.

y(t)=−t²+14t−40

Which of the following statements are true about the graph of y(t) for
6≤t≤8 and WHY?

a. The value of y(t) increases over the interval 6≤t≤7

b. The value of y(t) increases over the interval 7≤t≤8

c. The average rate of change over the interval 6≤t≤8 is 0

d. The value of y(t) is constant over the interval 6≤t≤8

e. The average rate of changer over the interval 6≤t≤7 is the same as the average rate of change over the interval 7≤t≤8

Answer 1

from the given the function, y(t)=−t²+14t−40; the graph will be as shown below:
From the graph, it is evident that between the intervals 6≤t≤8:
The value of our function decreases over the given interval. Hence the answer is:
a. The value of y(t) increases over the interval 6≤t≤7