Answer:
Step-by-step explanation:
c(t)=40:0≤t≤400
=40+0.50 (t-400):t≥400
Answer:
Zero
Step-by-step explanation:
Since the line is a horizontal line, the slope does not change. The slope is zero.
Answer:
option 3
Step-by-step explanation:
Since definition of slope is:

the ratio:

explains the best (Ratio option 3)