Algebra & Functions

Question 1

For a function, every value of x must…

Answer 1

Map uniquely onto a value of y.

One to one OR many to one

NOT one to many/many to many

Question 2

x ∈ IR means..

Answer 2

x is a member of the set of all real numbers

Question 3

Domain means..

Answer 3

The values x can take.

Question 4

Range means..

Answer 4

The values y can take.

Question 5

fg(x)=

Answer 5

f(g(x))

Question 6

What does f:x I–> 2x+3 mean?

Answer 6

y=2x+3 or f(x)=2x+3

Question 7

Is x²+y²=9 a function?

Why or why not?

Answer 7

No.

One/many value(s) of x ≉ ONE value of y

Question 8

How do you find a minimum value on an x² (symmetrical) graph?

Answer 8

Substitute into the equation the value of x which is halfway between the two values of x where y=0

Question 9

How do you find eg. fg(2) ?

Answer 9

Find g(2) and substitute the answer into f(x) - less complicated than finding fg(x) and substituting in 2 (although both methods are technically correct).

Question 10

Where is the line of symmetry between f(x) and f^-1(x)?

Answer 10

y=x

Question 11

How do you find f^-1(x)

Answer 11

Take f(x) and swap x and y around, then make y the subject.

Question 12

The domain of f(x) is the ______ of f^-1(x).

Answer 12

Range

Question 13

If f(x)=f^-1(x), the graph is…

Answer 13

Self-inverse