FUNCTIONS ONE

Question

True or False: The relation y = x³ – 5 is a function.

Select one:

True

False

True or False: The relation x = y²is a function.

Select one:

True

False

What is the domain of the ordered pairs (5, 12) and (–3, –3)?

Select one:

a. 23

b. 

c. 

d. 17

 

Answer 1

1)

The relation y = x³ – 5

Draw the table for the relation.

x	f
-5	-130
-4	-69
-3	-32
-2	-13
-1	-6
0	-5
1	-4
2	3
3	22
4	59
5	120

From the table draw the graph for the relation

For each value of x, this vertical line passes through no more than one point on the graph.
Thus, the graph represents a function.

Option true is correct.

 

Answer 2

2)

The curve y² = x represents a parabola rotated 90° to the right.

We actually have 2 functions,

y = √x (the top half of the parabola); and

y = −√x (the bottom half of the parabola)

Here is the curve y² = x. It passes through (0, 0) and also (4,2) and (4,−2).

We get 2 values of y for each value of x larger than 0. This is not a function, it is called a relation.

False

Answer 3

Ordered pairs (5, 12) and (–3, –3)

Domain is the set up x-components in the ordered pairs.

So {5,-3} is the domain