Functions and Graphs

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Algebra 2 › Functions and Graphs

Questions 1 - 10
1

A circle is graphed by the equation What is the distance from the center of the circle to the point on a standard coordinate plane?

Explanation

First determine the center of the circle. The "x-3" portion of the circle equation tells us that the x coordinate is equal to 3. The "y-3" portion of the circle equation tells us that the y coordinate is equal to 3 as well. Therefore, the center of the circle is at (3,3).

To find the distance between (3,3) and (0,0), it is necessary to use the Pythagorean Theorem . Where "a" and "b" are equal to 3

(to visualize, you may draw the two points on a graph, and create a triangle. The line connecting the two points is the hypotenuse, aka "c." )

2

What is the center of the circular function ?

Explanation

Remember that the "shifts" involved with circular functions are sort of like those found in parabolas. When you shift a parabola left or right, you have to think "oppositely". A right shift requires you to subtract from the x-component, and a left one requires you to add. Hence, this circle has no horizontal shift, but does shift 6 upward for the vertical component.

You can also remember the general formula for a circle with center at and a radius of .

Comparing this to the given equation, we can determine the center point.

The center point is at (0,6) and the circle has a radius of 5.

3

What is the center and radius of the following equation, respectively?

Explanation

The equation given represents a circle.

represents the center, and is the radius.

The center is at:

Set up an equation to solve the radius.

The radius is:

The answer is:

4

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 .

5

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 .

6

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 .

7

What is the domain of the following function? Please use interval notation.

Explanation

A basic knowledge of absolute value and its functions is valuable for this problem. However, if you do not know what the typical shape of an absoluate value function looks like, one can always plug in values and plot points.

Upon doing so, we learn that the -values (domain) are not restricted on either end of the function, creating a domain of negative infinity to postive infinity.

If we plug in -100000 for , we get 100000 for .

If we plug in 100000 for , we get 100000 for .

Additionally, if we plug in any value for , we will see that we always get a real, defined value for .

**Extra Note: Due to the absolute value notation, the negative (-) next to the is not important, in that it will always be made positive by the absolute value, making this function the same as . If the negative (-) was outside of the absolute value, this would flip the function, making all corresponding -values negative. However, this knowledge is most important for range, rather than domain.

8

Identity

Explanation

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

9

What is the domain of the function ?

Explanation

The expression under the square root symbol cannot be negative, so to find the domain, set that expression .

The domain includes all x-values less than or equal to 7, which can be written as .

10

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:

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