Functions and Graphs

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Math › Functions and Graphs

Questions 1 - 10
1

Determine whether each function represents exponential decay or growth.

a) decay

b) growth

a) growth

b) growth

a) decay

b) decay

a) growth

b) decay

Explanation

a)

This is exponential decay since the base, , is between and .

b)

This is exponential growth since the base, , is greater than .

2

Find the equation of the line passing through the points and .

Explanation

To calculate a line passing through two points, we first need to calculate the slope, .

Now that we have the slope, we can plug it into our equation for a line in slope intercept form.

To solve for , we can plug in one of the points we were given. For the sake of this example, let's use , but realize either point will give use the same answer.

Now that we have solved for b, we can plug that into our slope intercept form and produce and the answer

3

Find the y-intercept of the following line.

Explanation

To find the y-intercept of any line, we must get the equation into the form

where m is the slope and b is the y-intercept.

To manipulate our equation into this form, we must solve for y. First, we must move the x term to the right side of our equation by subtracting it from both sides.

To isolate y, we now must divide each side by 3.

Now that our equation is in the desired form, our y-intercept is simply

4

What are the coordinates of the center of a circle with the equation ?

Explanation

The equation of a circle is , in which (h, k) is the center of the circle. To derive the center of a circle from its equation, identify the constants immediately following x and y, and flip their signs. In the given equation, x is followed by -1 and y is followed by -6, so the coordinates of the center must be (1, 6).

5

What is the domain and range of the following graph?

Graph for questions

Domain: All real numbers

Range:

Domain:

Range: All real numbers

Domain: All real numbers

Range:

Domain:

Range: All real numbers

Domain: All real numbers

Range: All real numbers

Explanation

Domain looks at x-values and range looks at y-values.

The x-values appear to continue to go on forever, which suggests the answer:

"all real numbers"

The y-values are all number that are equal to nine or less which is

So you answer is:

Domain: All real numbers

Range:

6

Identity

Explanation

All inputs are valid. There is nothing you can put in for x that won't work.

7

Based on the figure below, which line depicts a quadratic function?

Question_10

Red line

Blue line

Green line

Purple line

None of them

Explanation

A parabola is one example of a quadratic function, regardless of whether it points upwards or downwards.

The red line represents a quadratic function and will have a formula similar to .

The blue line represents a linear function and will have a formula similar to .

The green line represents an exponential function and will have a formula similar to .

The purple line represents an absolute value function and will have a formula similar to .

8

Consider the equation:

The vertex of this parabolic function would be located at:

Explanation

For any parabola, the general equation is

, and the x-coordinate of its vertex is given by

.

For the given problem, the x-coordinate is

.

To find the y-coordinate, plug into the original equation:

Therefore the vertex is at .

9

What are the -intercepts of the equation?

There are no -intercepts.

Explanation

To find the x-intercepts of the equation, we set the numerator equal to zero.

10

Consider the following two functions:

and

How is the function shifted compared with ?

units left, units down

units right, units down

units left, units up

units right, units down

units left, units down

Explanation

The portion results in the graph being shifted 3 units to the left, while the results in the graph being shifted six units down. Vertical shifts are the same sign as the number outside the parentheses, while horizontal shifts are the OPPOSITE direction as the sign inside the parentheses, associated with .

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