Question

In Exercises, use a graphing utility to graph the function. $$ y=4^{x}+3 $$

Short answer

The function \(y = 4^x + 3\) is an exponential function with base 4 and a vertical shift of +3. It approaches the y-axis but never touches it for negative values of \(x\) and increases steeply for positive values. The graph is drawn using a graphing utility.

Step-by-step solution

Understand the function

The function \(y = 4^x + 3\) is an exponential function. The base of the exponent is 4 and 3 is a vertical shift. When \(x\) is lower, for example, -2, -1, 0- the function will approach 0 but won't reach it. The function will increase steeply for positive values of \(x\), for example, 1, 2. The +3 shifts the function three units upwards.

Input values into the function

Choose some values for \(x\) and find corresponding \(y\) to draw some points on the graph. For instance, for \(x= -2, -1, 0, 1, 2\) we get \(-3/4, 1/4, 3, 7, 19\) respectively.

Draw the graph

Now, use a graphing utility to draw the function. Plot points from step 2 on the graph. The graph will start close to the y-axis due to the vertical shift +3 and approach the y-axis but never touch it.

Key concepts

Graphing Utilities

Graphing utilities are computerized tools or software that help visualize mathematical functions by generating their graphs. These utilities can take an equation, like our exponential function \(y = 4^x + 3\), and display its graph on a virtual or physical screen. They are especially useful in mathematics because they provide a visual representation that makes understanding functions easier.

To use a graphing utility effectively, start by entering the function into the tool. Most utilities will allow you to input equations directly, using either manual entry or by selecting the function type. Once the function is entered, you can usually adjust settings such as zoom levels and axes ranges to better view the graph. This is particularly helpful for complicated functions or when you need to see more detail at specific parts of the graph. Additionally, many graphing utilities offer features like plotting specific points, finding intersections, and showcasing calculated values on the graph.

Using graphing utilities with functions like \(y = 4^x + 3\) helps in visualizing the rapid growth of exponential functions, clearly showing key features like asymptotes where the graph approaches but never touches.

Vertical Shifts

Vertical shifts occur when a constant is added or subtracted from the function's output. In our example, the function \(y = 4^x + 3\) includes a vertical shift upwards by 3 units. This means every point on the graph of \(y = 4^x\) is moved three units up.

Understanding vertical shifts is key to graphing functions accurately. When a function like \(y = 4^x\) has a constant added, you can interpret this as the whole graph moving up (or down if the constant were negative) along the y-axis. This shift does not affect the horizontal position of any point on the graph, so the shape remains the same.

Here are some things to remember about vertical shifts:

• Positive shifts (like +3) move the graph up.
• Negative shifts move the graph down.
• The graph's shape and steepness are unchanged.
• The horizontal asymptote (if any) is also shifted vertically.

Function Graphing

Function graphing is the process of displaying a mathematical function's behavior on a coordinate system. In the case of \(y = 4^x + 3\), we're dealing with graphing an exponential function that involves base 4. Exponential functions have unique characteristics that distinguish them from other types of functions, such as linear or quadratic.

To effectively graph a function like \(y = 4^x + 3\), start by determining some key points by substituting various values for \(x\) into the equation. These computations provide you with the coordinates needed for accurate plotting on the graph. For instance, substituting \(x = -2, -1, 0, 1,\) and \(2\) gives the points \((-2, -\frac{3}{4}), (-1, \frac{1}{4}), (0, 3), (1, 7),\) and \((2, 19)\).

Once you have these points, plot them on the graph and draw a smooth curve through them. The exponential curve will tend to rise steeply on one side due to the nature of exponential growth, while the vertical shift from '+3' will ensure that the entire graph rests three units higher than the base function \(y = 4^x\). This combination of selecting key points and understanding shifts ensures a clear graph that accurately represents the function's behavior.