Understanding the basic graphs and the way translations apply to them, we will recognize each Graphs, we are able to obtain new graphs that still have all the properties of the old ones. There are some basic graphs that we have seen before. Mathematics presented to you without making the connection to other parts, you will 1) becomeįrustrated at math and 2) not really understand math.
Which makes comprehension of mathematics possible. You can understand the foundations, then you can apply new elements to old. Part of the beauty of mathematics is that almost everything builds upon something else, and if Reflection A translation in which the graph of a function is mirrored about an axis. Scale A translation in which the size and shape of the graph of a function is changed.
#Reflection over y axis how to#
The last step is to divide this value by 2, giving us x = 4 as our axis of symmetry! Let's take a look at what this would look like if there were an actual line there:Īnd that's all there is to it! For further study with transformations of a functions with regards to trigonometric functions, see our lessons on transformations of trig graphs and how to find trigonometric functions by graphs.1.5 - Shifting, Reflecting, and Stretching Graphs 1.5 - Shifting, Reflecting, and Stretching Graphs Definitions Abscissa The x-coordinate Ordinate The y-coordinate Shift A translation in which the size and shape of a graph of a function is not changed, but Now, by counting the distance between these two points, you should get the answer of 8 units. Let's pick the origin point for these functions, as it is the easiest point to deal with. The best way to practice finding the axis of symmetry is to do an example problem:įind the axis of symmetry for the two functions show in the image below.Īgain, all we need to do to solve this problem is to pick the same point on both functions, count the distance between them, and divide by 2. This is because, by it's definition, an axis of symmetry is exactly in the middle of the function and its reflection. In this case, all we have to do is pick the same point on both the function and its reflection, count the distance between them, and divide that by 2. It can be the y-axis, or any vertical line with the equation x = constant, like x = 2, x = -16, etc.įinding the axis of symmetry, like plotting the reflections themselves, is also a simple process. The axis of symmetry is simply the vertical line that we are performing the reflection across. But before we go into how to solve this, it's important to know what we mean by "axis of symmetry". In some cases, you will be asked to perform vertical reflections across an axis of symmetry that isn't the y-axis. Step 3: Divide these points by (-1) and plot the new pointsįor a visual tool to help you with your practice, and to check your answers, check out this fantastic link here. Step 2: Identify easy-to-determine points Step 1: Know that we're reflecting across the y-axis Below are several images to help you visualize how to solve this problem. Don't pick points where you need to estimate values, as this makes the problem unnecessarily hard. When we say "easy-to-determine points" what this refers to is just points for which you know the x and y values exactly. Remember, the only step we have to do before plotting the f(-x) reflection is simply divide the x-coordinates of easy-to-determine points on our graph above by (-1). Given the graph of y = f ( x ) y=f(x) y = f ( x ) as shown, sketch y = f ( − x ) y = f(-x) y = f ( − x ). The best way to practice drawing reflections over y axis is to do an example problem: In order to do this, the process is extremely simple: For any function, no matter how complicated it is, simply pick out easy-to-determine coordinates, divide the x-coordinate by (-1), and then re-plot those coordinates.
One of the most basic transformations you can make with simple functions is to reflect it across the y-axis or another vertical axis. Before we get into reflections across the y axis, make sure you've refreshed your memory on how to do simple vertical translation and horizontal translation.