411 REFERENCE · Wikibooks
Arithmetic Course/Function Definition
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Function
Function is a mathematical expression representing the relation of one quantity with another quantity. For example
Function of one variable f(x)
Function of two variables f(x,y)
Function of three variables f(x,y,z)
Basic Functions
Straight Line Function
f(x) = x
y = x
x | -2 -1 0 1 2
y | -2 -1 0 1 2
A function of a straight line that goes through point (0,0)
200px
/Slope-intercept form/
Two-point form
Two points also uniquely determine a line. Given points and , we have the equation
This presentation is in the two-point form. It is essentially the same as the point-slope form except we substitute the expression for m.
Parabola Function
f(x) = x2
y = x2
x | -2 -1 0 1 2
y | 4 -1 0 1 4
A function of a parabola that goes through point (0,0)
200px
Hyperbole Function
f(x) = x3
y = x3
x | -2 -1 0 1 2
y | -8 -1 0 1 8
A function of a hyperbola that goes through point (0,0)