Domain and Range

The domain of a function is all the possible x values which will make the function "work" by outputting real values.

When finding the domain, remember:
denominator (bottom) of a fraction cannot be zero
the values under a square root must be positive

The range of a function is the possible y values of a function resulting when we substitute all the possible x-values.

When finding the range, remember:
substitute different x-values into the expression for y to see what is happening
make sure you look for minimum and maximum values of y

You may even want to draw a sketch of the graph.

http://www.intmath.com/Functions-and-graphs/2a_Domain-and-range.php

Domain= D=(x)
Range=R=(y)

Example: (2,4),(2,7),(5,6),(3,8)

D=(x) so the domain must be; {2,2,5,3}

R=(y) so the range must be;{4,7,6,8}



Take the graph: y=2-x



The x-intercept is at (2,0) and the y-intercept is at (0,-2)






Domain- x1,x2, all real numbers

Range-y1,y2, all real numbers

So from the graph above the Domain and range would be:

D= {2,0}

R= {0,-2}

http://block5applied.blogspot.com/

Some Links that you may find helpful are:

http://www.purplemath.com/modules/fcns2.htm

http://www.freemathhelp.com/domain-range.html

http://mathdemos.gcsu.edu/mathdemos/domainrange/domainrange.html

http://mathforum.org/library/drmath/sets/select/dm_domain_range.html