3.7
Equations that represent functions are often written in
function notation.
f(x) is used in place of y in function notation.
y = mx + b
becomes
f(x) = mx + b
If I want to evaluate for a number, I can plug the number in
for x
f(#) means to plug the # in for x in order to evaluate.
***can use other letters. For example g(x), h(x),…
Evaluate the function y = 3x + 2 for x = -2, 0, and 3
X = -2:
X = 0:
X = 3:
Evaluate the function f(x) = 3x + 2 for x = -2, 0, and 3
X = -2:
X = 0:
X = 3:
Evaluate when x = 4
f(x) = 3x – 2
g(x) = -2x + 7
h(x) = ½x - 5
Given y = 3x + 4, find the value of x so that y = 10
Given f(x) = -2x+10, find the value of x so that f(x) = -6
c.
f ( x) 2 x 5; 9
2
g ( x) x 6; 14
3
h( x) 4 x 18; 8
A family of functions is a group of functions with similar
characteristics. For instance, linear functions of the form
g(x) = mx + b is a family of functions. The most basic form
of this equation is f(x) = x. This is called the parent
function.
2
g ( x) x
3
pp. 203-204: 3, 7, 11, 15-21 odd, 23, 25, 31, and 33