Functions (mathematics)/Graphs/Linear function

Linear function

$f(x)=x$

$f(x)=-x$

$f(x)=ax$

$f(x)=-ax$

$f(x)=ax+b$

$f(x)=-ax+b$

Graphs

f(x) = x

Let f(x)=y . Then the value of y for all x are

x:	-3	-2	-1	0	1	2	3
y:	-3	-2	-1	0	1	2	3

Plot these x,y gives a graph of a straight line which has positive slope of 1 that pass through origin at (0,0)

f(x) = -x

Let f(x)=y . Then the value of y for all x are

x:	-3	-2	-1	0	1	2	3
y:	3	2	1	0	1	2	3

Plot these x,y gives a graph of a straight line which has negative slope of 1 that pass through origin at (0,0)