Functions

Question 1

what is a relation?

Answer 1

Any set of ordered pairs

Question 2

What is a function?

Answer 2

A set of ordered pairs in which each x coordinate has a unique y coordinate.

Question 3

How do you see if a graph is a function?

Answer 3

Vertical line test: draw a vertical line, if it touches the preexisting line more than once it is not a function.

Question 4

How do you invert a function?

Answer 4

Interchange x and y then make y the subject.

Question 5

How do you find the domain?

Answer 5

See if subbing any numbers as x forces you to root a negative number.

Question 6

How do you find the range?

Answer 6

See if subbing any numbers as y or f(x) forces you to root a negative.

Question 7

What do you do if a question asks you to evaluate several functions?

Answer 7

See which function fits in each domain and multiply or square accordingly.

Question 8

How do you draw a function?

Answer 8

Sub in the standard points including 0,1,2,3,-1,-2,-3

Question 9

How do you do a question that has multiple equations with f(x) f(k) etc

Answer 9

Use substitution, for example if f(x)=x2+10x+25 then f(k)=k2+10k+25