All Algebra II Resources
Example Questions
Example Question #11 : Transformations Of Parabolic Functions
Write the equation for shifted 4 units up and 5 units to the left.
Right now, the vertex for this point is , so to shift it up 4 and left 5 would place it at .
This gives us an equation of .
We could also get this by adding 5 inside the parentheses for the left 5 shift, and adding 4 on the outside for the up 4 shift.
Example Question #31 : Parabolic Functions
Give the equation of the parabola reflected over the -axis.
Flipping this equation over the x-axis means that the sign of y changes.
The easiest way to accomplish this is just to multiply everything by -1.
Example Question #13 : Transformations Of Parabolic Functions
Which would be the equation of when reflected over the -axis?
To flip this over the -axis, the sign of x changes.
This entails changing to .
.
Perhaps a simpler way to think about this is that the vertex for this parabola is at .
If we flip the equation over the y-axis, it will place the vertex at , making our new equation .
Example Question #14 : Transformations Of Parabolic Functions
Write the equation for the parabola shifted 3 units to the right and then reflected across the -axis.
To solve this problem, we could complete the square and shift the equation that way, but the vertex ends up being so this may not be an ideal method. Instead, we know we're shifting the equation 3 units to the right, so we can just plug in for every appearance of x:
To simplify, first expand
Now we can plug that in and continue simplifying:
distribute the 2; combine -3 and -5
combine like terms -12x and x; 18 and -8
Now we want to flip this over the x-axis, meaning that the y coordinates change sign.
This means we have to multiply everything by -1, or simply change the sign of every term on the right side:
Example Question #41 : Parabolic Functions
Describe the translation in
from the parent function
.
Up three units, left one unit
Up three units, right one unit
Down three units, right one unit
Down three units, left one unit
Down three units, right one unit
Below is the standard equation for parabolas;
Therefore,
and
thus,
the translation from the parent function is down three units, right one unit.
Example Question #14 : Transformations Of Parabolic Functions
Given the parabola , what is the new equation if the parabola is shifted left two units, and up four units?
Shifting up and down will result in a change in the y-intercept.
Add four to the equation.
Shifting the parabola to the left two units will change the inner term to , which will be .
Replace the quantity with .
The new equation is:
Example Question #15 : Transformations Of Parabolic Functions
Shift to the left two units and up two units. What is the new equation?
Vertical shifts will change the value of the y-intercept. Since this function is to be shifted up two units, add two to the right side of the equation.
This graph shifted two units to the left indicates that its zeros will also shift to the left two units, which means that the term will become .
Rewrite the equation and expand the binomials.
The new equation is:
Example Question #16 : Transformations Of Parabolic Functions
Shift the parabola three units to the right. What is the new equation?
Shifting this graph three units to the right means that the x-variable will need to be replaced with . Rewrite the equation.
Use the FOIL method to simplify the binomial.
Simplify the right side.
The equation becomes:
The answer is:
Example Question #42 : Parabolic Functions
3 spaces right
3 spaces up
3 spaces down
3 spaces left
3 spaces right
Example Question #43 : Parabolic Functions
Which of the below quadratic functions will be the widest?
To determine how "wide" or "skinny" a parabola is, we look at the leading coefficient.
The smaller the fraction, the wider a parabola will be.
The larger the whole number, the skinnier the parabola will be.
This will give us the widest parabola.