Big Ideas Math Algebra 1, 2015
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Big Ideas Math Algebra 1, 2015 View details
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Exercise 17 Page 558

Review the average rate of change formula.

See solution.

Practice makes perfect

We are asked to compare the average rates of change for the functions g(x) and h(x) over the interval x= 0 to x= 3. To do so, we will calculate each of the average rates of change one at a time.

Average Rate of Change of g(x)

We are given the graph of a square root function g(x).

Graph of g
To find the average rate of change over the interval x= 0 to x= 3, we will first remember the corresponding formula. Average Rate of Change = g( x_2)-g( x_1)/x_2- x_1 As we can see from the graph, g( 0)=0 and g( 3)=3. Let's substitute these values into the formula.
Average Rate of Change = g(x_2)-g(x_1)/x_2-x_1
Average Rate of Change =3-0/3- 0
Average Rate of Change=3/3
Average Rate of Change= 1

Average Rate of Change of h(x)

Next, we will find the average rate of change of the cube root function h(x) over the same interval, [ 0, 3]. h(x) = sqrt(32x) Let's apply the same formula one more time. Average Rate of Change = h( x_2)-h( x_1)/x_2- x_1 This time we will need to calculate h( 3) and h( 0) before we can find the average rate of change.

Substitution Result
h(3) sqrt(3/2( 3)) ≈ 1.65
h(0) sqrt(3/2( 0))
h(3)-h(0) 1.65- ≈ 1.65
h(3)-h(0)/3-0 1.65/3 ≈ 0.55

The average rate of change of h(x) over the given interval is about 0.55.

Comparison of the Average Rates of Change

Finally, let's compare the average rates of change. 1 > ≈0.55 We can conclude that the average rate of change of the square root function g(x) is greater than average rate of change of the cube root function h(x) over the interval [ 0, 3].