Answer: 72 miles.
Step-by-step explanation:
We know the relationship:
Distance = speed*time.
Then we can write the equation for distance as a function of time for Ali as:
A(t) = 12mph*t
where t is time in hours.
Fatimah's equation will be:
F(t) = 18mph*(t - 2h)
where the -2h appears because she starts two hours after Ali.
Fatimah will overtake Ali when F(t) = A(t) (their positions are the same)
Then we need to solve:
12mph*t = 18mph*(t - 2h)
12mph*t = 18mph*t - 18mph*2h
12mph*t = 18mph*t - 36 mi
36 mi = (18mph - 12mph)*t
36mi = 6mph*t
36mi/6mph = t
6h = t
So Ali travels for 6 hours before he gets overtaken, then the total distance that Ali travels is:
A(6h) = 12mph*6h = 72 mi
Use Pythagorean theorem to solve.
a^2 + b^2 = c^2
6^2 + b ^2 = 14^2
36 + b^2 = 196
Subtract 36 from both sides.
b^2 = 196-36
b^2 = 160
Take the square root of both sides.
b = sqrt 160
As a decimal
b = 12.649
As a simplified radical
b = 4sqrt10
Part A:
The average rate of change refers to a function's slope. Thus, we are going to need to use the slope formula, which is:
and 
are points on the function
You can see that we are given the x-values for our interval, but we are not given the y-values, which means that we will need to find them ourselves. Remember that the y-values of functions refers to the outputs of the function, so to find the y-values simply use your given x-value in the function and observe the result:
Now, let's find the slopes for each of the sections of the function:
<u>Section A</u>
<u>Section B</u>
Part B:
In this case, we can find how many times greater the rate of change in Section B is by dividing the slopes together.
It is 25 times greater. This is because 
is an exponential growth function, which grows faster and faster as the x-values get higher and higher. This is unlike a linear function which grows or declines at a constant rate.
