Math 1011 Precalculus

Notebook Author/Course Instructor: Barry McQuarrie
Date: Spring 2006
Lecture topic: Average Rate of Change

This was created from a Mathematica notebook to give you an opportunity to practice some average rate of change problems. You will be learning Mathematica when you get to Calculus! So don't worry about the Clear command, I am just erasing the computers memory.

For each problem, work out the quantities (f(x + h) - f(x))/h, (f(x + h) - f(x - h))/(2h), and f(3)-f(4) and simplify. Come and see me if you have any questions.

Note: The goal with the simplifications for the quantities (f(x + h) - f(x))/hand (f(x + h) - f(x - h))/(2h)is to simplify to the point where substitution of h=0 does not lead to an indeterminant form (remember 0/0 is an indeterminant form). Use the handout for Average Rate of Change to help you decide what algebraic simplifications would be appropriate for each problem (ie, expanding powers, finding a common denominator, or rationalizing the numerator). Click on the link to see the solution.

Problem 1

In[1]:=

Clear[f]

f[x_] = 15x^2 + 3x + 5

Out[2]=

5 + 3 x + 15 x^2

Solution

Problem 2

In[11]:=

Clear[f]

f[x_] = (x - 10)^2

Out[12]=

(-10 + x)^2

Solution

Problem 3

In[21]:=

Clear[f]

f[x_] = 1/(x + 4)

Out[22]=

1/(4 + x)

Solution

Problem 4

In[31]:=

Clear[f]

f[x_] = 1/(x^2 - 2)

Out[32]=

1/(-2 + x^2)

Solution

Problem 5

In[41]:=

Clear[f]

f[x_] = (x - 7)^3 + 3x

Out[42]=

(-7 + x)^3 + 3 x

Solution

Problem 6

In[51]:=

Clear[f]

f[x_] = x^(1/2)

Out[52]=

x^(1/2)

Solution

Problem 7

In[61]:=

Clear[f]

f[x_] = (x + 9)^(1/2)

Out[62]=

(9 + x)^(1/2)

Solution

Problem 8

In[71]:=

Clear[f]

f[x_] = (x + 16)^(1/2)/2

Out[72]=

(16 + x)^(1/2)/2

Solution

Problem 9

In[81]:=

Clear[f]

f[x_] = (x + 1)/(x + 2)

Out[82]=

(1 + x)/(2 + x)

Solution

Problem 10

In[91]:=

Clear[f]

f[x_] = 7 - 1/(x + 1)

Out[92]=

7 - 1/(1 + x)

Solution


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