Measures how quickly the position of the object changes when time advances.
The derivative of a function of a single variable at a chosen input value, when it exists, is the slope of the tangent line to the graph of the function at that point. The tangent line is the best linear approximation of the function near that input value
Answer:

Step-by-step explanation:
GIVEN: In a
mile race, Janet covered the first
miles at a constant rate. She then speed up and rode her bike the last
miles at a rate that was
miles per minute faster. Janet's overall time would have been
minutes faster had she ridden her bike the whole race at the faster pace.
TO FIND: What was Janet's average speed (in miles per minute) for the whole race?
SOLUTION:
let the speed of Janet in first

speed of Janet's bike in last

total time taken by Janet,


Time taken if Janet rides whole race at faster pace 
As, Janet's overall time would have been
faster had she ridden her bike the whole race at the faster pace.




on solving we get





Average speed 
Average speed 
Therefore average speed of Janet was 
Answer:
B
Step-by-step explanation:
10 + 9 = 19
16x4=64; so we need two numbers that add up to 16 and their product should be 64. So x=8
Answer:
(-15,0) and (0,-3)
Step-by-step explanation:
(-15,0) = x- intercept
(0,-3) = y-intercept