3. Functions Flashcards
What is a function like
A number machne
Input of function
Domain (x)
Domain (x)
An input of function
Output of function
Range (y)
Range (y)
Output of function
How are functions written
f (x)
Given g (x) = 3x^2 - x, find the value of g (x-2)
3x2 - 13x + 14
Method for solving basic function
- Write our function
- Sub domain into function
- Simplify
If h(x) = x / (2x +3), simplify h (1/x)
1 / 2 + 3x
Two restrictions on domain
You can’t take the square root of a -ve
You can’t divide by 0
What does a restriction on the domain mean
Function will be undefined for a certain value of x
Find for
Find for what value (s) of x is f(x) undefined and state a suitable domain
for (x) = /(x-3)
x is undefined when x - 3 < 0, x < 3
domain = x greater than or equal to 3
Find for what value (s) of x is f(x) undefined and state a suitable domain
f(x) = 1 / x(x+5)
x ≠ 0, -5
Set
Collection of items with a common property
Collection of items with a common property
Set
Element/member
An item in a set
An item in a set
Element/member
N set
Natural numbers
Natural numbers
N
W set
Whole numbers
Whole numbers
W set
Z set
Integers
Integers
Z set
Q set
Rational numbers
Rational numbers
Q set