Sunday, January 14, 2007
posted by dondelacruz_ at 10:18 AM
Today we did more on functions

What Is a Function you ask?

A function is a special type of relation where each x-value in the domain corresponds to ONLY 1 y-value in the range.

example: Graph f(x)= x-1 means the same as y=x-1



D:{xER}
R:{xER}

y-intercept --> f(0)=x-1
=0-1
=-1




the zeros of the function are the x-intercept(let y=0)
f(x)=x-1
0=x-1
1=x

to find zero let F(x)= 0

Graph, find D and R and the zeros for f(x)=3/2x-3



D:{xER}
R:{xER}

zeros: f(x)=3/2x-3
0=3/2x-3
2(3)=(3/2)2x
6=3x
2=x


f(x)=1/2x-3
0=1/2x-3
2(3)=(1/2)2x
6=x

linear functions f(x)=mx+b
constant functions f(x)=b <-- has no x value

will always be a straight line.
f(x)=-4



HOMEWORK: ex. 54 # 1-9, 12
55 # 1-7