Functions and Graphs
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Math › Functions and Graphs
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
.
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
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
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).
What is the domain and range of the following graph?

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