Adding & Subtracting

Adding and Subtracting

Site: | TBAISD Moodle |

Course: | Michigan Algebra I Preview 2012 |

Book: | Adding & Subtracting |

Printed by: | Guest user |

Date: | Saturday, July 20, 2019, 02:39 PM |

Adding

The four main operations of addition, subtraction, multiplication, and division can also be performed with functions. To add functions, combine like terms. *Step 1.* Replace *f(x)* and *g(x)* with their equivalent expressions.

*f*(*x*) + *g*(*x*)

(2*x ^{2}*) + (3

*Step 2.* Eliminate the parentheses and combine like terms.

2*x ^{2}* + 3

5*x ^{2}* + 1

Subtracting

To subtract functions, first change the sign of every term being subtracted using the *Step 1.* Replace *f(x)* and *g(x)* with their equivalent expressions.

*f*(*x*) - *g*(*x*)

(2*x ^{2}*) - (3

*Step 2.* Use the *Distributive Property* to change the sign of every term of g(x).

2*x ^{2}* - 3

*Step 3.* Combine like terms.

-1*x*^{2 }- 1 or -*x*^{2} - 1

Evaluating

Functions can also be added or subtracted given a domain value. First evaluate each function for the given domain then perform the indicated operation using the output values.

**Example ** If *f(x*) = 2*x ^{2}* and

*Step 1.* Evaluate each function

** **

*f*(2) = 2(2)^{2} = 8

*g*(3) = 3(3)^{2} + 1 = 28

*Step 2.* Add the output values of the two functions

*f* (2) + *g(*3)

= 8 + 28

= 36

Sources

Embracing Mathematics, Assessment & Technology in High Schools; A Michigan Mathematics & Science Partnership Grant Project

Holt, Rinehart & Winston, "Adding and Subtracting Functions." http://my.hrw.com/math06_07/nsmedia/lesson_videos/alg2/player.html?contentSrc=6480/6480.xml (accessed 8/10/2010).

Kuta Software, www.kutasoftware.com/free.html (accessed 07/19/2010).

Stapel, Elizabeth. "Function Notation: Introduction/Evaluation." http://www.purplemath.com/modules/fcnnot.htm (accessed 7/15/2010).