Unlock The Secrets Of F(x) = 49(1/7)^x: A Math Deep Dive

by Andrew McMorgan 57 views

Hey math enthusiasts! Today, we're diving deep into a super cool exponential function: f(x) = 49inom{1}{7}^x. We're going to break down its characteristics and figure out exactly what makes it tick. Get ready to explore its domain, range, and behavior as xx changes. Let's get this mathematical party started!

Understanding the Domain: Where Can xx Go?

Alright guys, let's talk about the domain of our function, f(x) = 49inom{1}{7}^x. The domain is basically all the possible x-values that you can plug into a function without breaking it. For most exponential functions like this one, there are no restrictions on the x-values. You can plug in positive numbers, negative numbers, zero, fractions – pretty much anything goes! So, if you're looking at the options, the true statement about the domain is that it is the set of all real numbers. This means xx can be absolutely any number you can think of on the number line. We're not limited here, folks! You can test it out: try plugging in a huge positive number, a tiny negative number, or even zero. The function will give you a valid output every single time. This is a fundamental property of exponential functions where the base is a positive number (and not equal to 1). The exponent can be anything, and the function remains well-defined. So, keep that in mind: The domain is the set of all real numbers. This is a crucial point to remember when analyzing exponential functions, as it's a common characteristic.

Exploring the Range: What Outputs Can We Get?

Now, let's shift our focus to the range of f(x) = 49inom{1}{7}^x. The range refers to all the possible y-values (or f(x) values) that the function can produce. For this specific type of exponential function, where the base inom{1}{7} is positive and the coefficient 49 is also positive, there's a specific pattern. The term inom{1}{7}^x will always be positive, regardless of the value of xx. Think about it: any positive number raised to any real power is always going to result in a positive number. Now, we're multiplying that positive result by 49. Since 49 is also positive, the final output, f(x)f(x), will always be a positive number. It can get incredibly close to zero, especially as xx gets larger and larger (approaching infinity), but it will never actually reach zero or become negative. Therefore, the range is y>0y>0. This means the output of our function will always be greater than zero. It's an important distinction from the domain, which can include all real numbers. The range is confined to the positive side of the y-axis. This property is key to understanding the behavior and graphing of exponential decay functions, which is what this function represents due to its base being between 0 and 1.

The Behavior as xx Approaches Infinity: What Happens Next?

Let's investigate how our function f(x) = 49inom{1}{7}^x behaves as xx gets really, really big. We're talking about what happens as xx approaches infinity. Remember, our base is inom{1}{7}, which is a number between 0 and 1. When you raise a number between 0 and 1 to a very large positive power, what happens? It gets smaller and smaller, approaching zero. Think about ( rac{1}{2})^2 = rac{1}{4}, ( rac{1}{2})^3 = rac{1}{8}, ( rac{1}{2})^{10} is tiny! So, as xx approaches infinity, the term inom{1}{7}^x approaches 0. Now, our function is f(x) = 49 imes inom{1}{7}^x. If inom{1}{7}^x is approaching 0, then multiplying it by 49 will also result in a value that approaches 0. So, as xx approaches infinity, f(x)f(x) approaches 0. This is a classic characteristic of exponential decay functions. The graph gets closer and closer to the x-axis but never actually touches or crosses it. This is why the range is y>0y>0. It's a direct consequence of the base being less than 1 and the input (xx) becoming infinitely large. It's a pretty neat concept that shows how these functions level off towards a specific value.

Function Intercepts: Where Does it Cross the Axes?

Let's talk about intercepts, specifically the y-intercept. The y-intercept is the point where the graph of the function crosses the y-axis. This happens when x=0x=0. So, to find the y-intercept for f(x) = 49inom{1}{7}^x, we just need to plug in x=0x=0:

f(0) = 49inom{1}{7}^0

Remember that any non-zero number raised to the power of 0 is equal to 1. So, inom{1}{7}^0 = 1.

f(0)=49imes1f(0) = 49 imes 1 f(0)=49f(0) = 49

This tells us that the y-intercept is at the point (0,49)(0, 49). This is also related to the initial value or the coefficient in front of the exponential term. Since the function's output is always positive (y>0y>0), it will never cross the x-axis. Therefore, there is no x-intercept. The function approaches the x-axis asymptotically, but it never touches it.

Base and Decay: What's Happening with the inom{1}{7}?

The base of our exponential function, inom{1}{7}, plays a critical role in its behavior. Since the base is a positive number that is less than 1 (i.e., 0 < inom{1}{7} < 1), this indicates that the function represents exponential decay. This means that as the input value xx increases, the output value f(x)f(x) decreases. This is precisely what we observed when we looked at the behavior as xx approaches infinity – the function values get smaller and smaller, tending towards zero. If the base had been greater than 1, we would have seen exponential growth instead, where the function values increase as xx increases. The coefficient 49 acts as a vertical stretch factor, but it doesn't change the fundamental nature of decay driven by the base.

Summary of Correct Answers:

Based on our exploration, let's pinpoint the three correct statements about f(x)=49inom{1}{7}^x:

  • A. The domain is the set of all real numbers. As we discussed, you can plug any real number into xx and get a valid output.
  • D. The range is y>0y>0. The function will always output positive values, never reaching zero or becoming negative.
  • E. As xx approaches infinity, f(x)f(x) approaches 0. This confirms the exponential decay nature of the function due to its base being between 0 and 1.

And there you have it, guys! We've successfully broken down the properties of f(x)=49inom{1}{7}^x. Keep practicing, and you'll become exponential function pros in no time!