Ordered Pairs On $f(x)=3(1/4)^x$ Graph

by Andrew McMorgan 39 views

Hey math whizzes and graph-hoppers! Today, we're diving deep into the fascinating world of exponential functions, specifically focusing on $f(x)=3

(1/4)x(1/4)^x. You guys know how much we love unraveling the mysteries of functions here at Plastik Magazine, and this one is a real gem. We're going to tackle the question: Which ordered pairs lie on the graph of this particular exponential function? Sounds like a challenge, right? But don't sweat it, because by the end of this article, you'll be an expert at spotting points that belong on this curve.

First things first, let's break down what an exponential function is. Unlike linear functions where the input variable xx is multiplied by a constant, in exponential functions, the input variable xx is in the exponent. This makes a huge difference in how the graph behaves. Our function, f(x)=3(1/4)xf(x)=3(1/4)^x, is a classic example. It has a base, which is (1/4)(1/4) in this case, and a coefficient, which is 33. The general form of an exponential function is often written as f(x)=abxf(x) = ab^x, where 'aa' is the initial value (when x=0x=0) and 'bb' is the growth or decay factor. In our case, a=3a=3 and b=(1/4)b=(1/4). Since bb is between 0 and 1, we know this is a decay function, meaning the graph will get smaller as xx gets larger. Pretty neat, huh?

Now, how do we determine if an ordered pair (x,y)(x, y) lies on the graph of f(x)=3(1/4)xf(x)=3(1/4)^x? It's actually simpler than you might think! An ordered pair (x,y)(x, y) lies on the graph of a function if, and only if, when you substitute the xx-value into the function, the result you get is the yy-value. In other words, yy must be equal to f(x)f(x). So, for our function, we need to check if y=3(1/4)xy = 3(1/4)^x. If this equation holds true for a given pair (x,y)(x, y), then that point is definitely chilling on the graph. If not, it's taking a rain check elsewhere.

Let's get our hands dirty with some examples. Suppose we're given the ordered pair (2,3/16)(2, 3/16). To see if it's on the graph of f(x)=3(1/4)xf(x)=3(1/4)^x, we plug in x=2x=2 and see if we get y=3/16y=3/16.

f(2)=3(1/4)2f(2) = 3(1/4)^2 f(2)=3(1/16)f(2) = 3(1/16) f(2)=3/16f(2) = 3/16

Bingo! Since f(2)f(2) equals 3/163/16, the ordered pair (2,3/16)(2, 3/16) does lie on the graph. Awesome!

What about another point, say (1,3/4)(1, 3/4)? Let's test it. We plug in x=1x=1:

f(1)=3(1/4)1f(1) = 3(1/4)^1 f(1)=3(1/4)f(1) = 3(1/4) f(1)=3/4f(1) = 3/4

Yup, this one also works! So, (1,3/4)(1, 3/4) is another point on our exponential curve. It's like finding hidden treasures on a map, guys!

But what if we have a point like (0,3)(0, 3)? Let's check. We plug in x=0x=0:

f(0)=3(1/4)0f(0) = 3(1/4)^0 Remember, any non-zero number raised to the power of 0 is 1. So, (1/4)0=1(1/4)^0 = 1. f(0)=3(1)f(0) = 3(1) f(0)=3f(0) = 3

Perfect! So, the ordered pair (0,3)(0, 3) is also on the graph. This point is actually quite special because it's the y-intercept, where the graph crosses the y-axis. For any exponential function in the form f(x)=abxf(x) = ab^x, the y-intercept is always (0,a)(0, a). In our case, a=3a=3, so the y-intercept is (0,3)(0, 3), which matches our calculation. It's always good when things line up, right?

Now, let's consider an ordered pair that doesn't lie on the graph, for instance, (2,1/16)(2, 1/16). We already calculated f(2)f(2) and found it to be 3/163/16. Since f(2)=3/16f(2) = 3/16 and not 1/161/16, the ordered pair (2,1/16)(2, 1/16) does not lie on the graph of f(x)=3(1/4)xf(x)=3(1/4)^x. This point is off the curve, maybe trying to find a different function to belong to.

So, to recap, the key to determining if an ordered pair (x,y)(x, y) belongs to the graph of f(x)=3(1/4)xf(x)=3(1/4)^x is to simply substitute the xx-value into the function and check if the output matches the yy-value. It's a straightforward substitution and check, and it works for any function, not just this exponential one. The more you practice, the quicker you'll become at spotting these points. Keep those calculators handy and your minds sharp, and you'll be mastering exponential graphs in no time! Remember, math is all about practice, and every problem you solve brings you one step closer to understanding these cool concepts. Let's keep exploring and learning together!

Understanding the Components of f(x)=3(1/4)xf(x) = 3(1/4)^x

Alright guys, let's break down the function f(x)=3(1/4)xf(x) = 3(1/4)^x even further. Understanding each piece will give you a solid foundation for analyzing exponential functions and determining which points belong to their graphs. We've already touched upon the general form f(x)=abxf(x) = ab^x, and now we'll apply it specifically to our function. The number 33 in front of the parenthesis is our 'aa' value, which represents the initial value or the y-intercept. This is the value of the function when x=0x = 0. As we saw, f(0)=3(1/4)0=3(1)=3f(0) = 3(1/4)^0 = 3(1) = 3. So, the point (0,3)(0, 3) is the y-intercept. This is a crucial point to identify because it anchors the graph. Think of it as the starting line for our exponential journey. Whether the function is growing or decaying, it always begins its characteristic curve from this y-intercept. For our function, since a=3a=3 is positive, the graph will be above the x-axis around the y-intercept. If aa were negative, the entire graph would be reflected across the x-axis.

The number inside the parenthesis, (1/4)(1/4), is our 'bb' value, which is the base of the exponential term. This base determines the rate of growth or decay. In this case, b=1/4b = 1/4. Since 0<b<10 < b < 1, the function exhibits exponential decay. This means that as xx increases, the value of (1/4)x(1/4)^x decreases, and consequently, f(x)f(x) decreases. For example, let's look at how the function behaves for increasing xx values:

  • When x=1x=1, f(1)=3(1/4)1=3(1/4)=3/4f(1) = 3(1/4)^1 = 3(1/4) = 3/4. The value dropped from 3 to 3/4.
  • When x=2x=2, f(2)=3(1/4)2=3(1/16)=3/16f(2) = 3(1/4)^2 = 3(1/16) = 3/16. The value dropped further from 3/4 to 3/16.
  • When x=3x=3, f(3)=3(1/4)3=3(1/64)=3/64f(3) = 3(1/4)^3 = 3(1/64) = 3/64. And it keeps getting smaller!

This steady, multiplicative decrease is the hallmark of exponential decay. The larger xx gets, the closer f(x)f(x) gets to zero, but it never actually reaches zero. This is because (1/4)x(1/4)^x will always be a positive number, no matter how large xx is, so 3(1/4)x3(1/4)^x will also always be positive. The x-axis (y=0y=0) acts as a horizontal asymptote for this function. This means the graph approaches the x-axis but never touches or crosses it.

If the base bb were greater than 1 (e.g., f(x)=3(4)xf(x) = 3(4)^x), we would have exponential growth, where the function's value increases rapidly as xx increases. The coefficient a=3a=3 scales the function vertically. If aa were larger, the initial value would be higher, and the graph would be stretched upwards. If aa were smaller (but still positive), the graph would be compressed vertically.

Understanding these components – the initial value aa and the base bb – is fundamental. They dictate the function's starting point, its direction (growth or decay), its rate of change, and its asymptotic behavior. When you're given an ordered pair (x,y)(x, y) and asked if it lies on the graph of f(x)=3(1/4)xf(x) = 3(1/4)^x, you're essentially checking if the relationship defined by these components holds true for that specific point. You're verifying if the (x,y)(x, y) coordinates satisfy the equation y=3(1/4)xy = 3(1/4)^x. It’s like checking if a suspect’s alibi (the ordered pair) matches the crime scene (the function’s equation). If it fits, they’re involved; if not, they’re innocent (of being on that specific graph).

So, when you encounter an ordered pair, the first step is to identify the xx and yy values. Then, substitute the xx value into the function f(x)=3(1/4)xf(x) = 3(1/4)^x. Calculate the result. Compare this result to the given yy value. If they are identical, the ordered pair lies on the graph. If they differ, the ordered pair does not lie on the graph. This process is consistent and reliable for any point and any function. Keep practicing this, and you'll get super speedy at it!

Practical Applications and Visualizing the Graph

So, why bother with ordered pairs and checking if they lie on the graph of functions like f(x)=3(1/4)xf(x)=3(1/4)^x? Well, understanding this concept is the bedrock for visualizing and interpreting graphs, which have tons of real-world applications, guys. Exponential decay, as modeled by our function, pops up everywhere. Think about radioactive decay, where the amount of a substance decreases exponentially over time. Or consider the depreciation of an asset, like a car, which loses value over the years. Even the dissipation of a drug in the bloodstream follows an exponential decay pattern. When we talk about ordered pairs lying on the graph, we're talking about specific moments or states in these processes. For instance, if we were modeling the decay of a radioactive isotope, an ordered pair might represent (time elapsed, amount of substance remaining). Checking if a point lies on the graph means verifying if that specific time and remaining amount combination is consistent with the decay model.

Visualizing the graph of f(x)=3(1/4)xf(x)=3(1/4)^x helps solidify this understanding. We know it's a decay function because the base (1/4)(1/4) is between 0 and 1. We know it passes through the point (0,3)(0, 3) because f(0)=3f(0)=3. As xx increases, the yy-values decrease and approach zero. For example, f(1)=3/4f(1)=3/4, f(2)=3/16f(2)=3/16, f(3)=3/64f(3)=3/64. The curve gets progressively closer to the x-axis. What about negative values of xx? Let's explore that a bit.

  • If x=−1x=-1, f(−1)=3(1/4)−1f(-1) = 3(1/4)^{-1}. Remember that raising a fraction to a negative exponent means taking the reciprocal of the fraction and making the exponent positive. So, (1/4)−1=41=4(1/4)^{-1} = 4^1 = 4. Therefore, f(−1)=3(4)=12f(-1) = 3(4) = 12. The ordered pair (−1,12)(-1, 12) lies on the graph.
  • If x=−2x=-2, f(−2)=3(1/4)−2f(-2) = 3(1/4)^{-2}. (1/4)−2=42=16(1/4)^{-2} = 4^2 = 16. Therefore, f(−2)=3(16)=48f(-2) = 3(16) = 48. The ordered pair (−2,48)(-2, 48) lies on the graph.

Notice that as xx becomes more negative (moves to the left on the number line), the yy-values increase rapidly. This means the graph shoots upwards as we move left from the y-intercept. So, the graph of f(x)=3(1/4)xf(x)=3(1/4)^x starts very high on the left side (as x o - ilde{oldsymbol{ ext{`}}}) and curves downwards, approaching the x-axis on the right side (as x o ilde{oldsymbol{ ext{`}}})).

When you're given a set of ordered pairs, you can plot them on a graph. If they all seem to follow this characteristic curve – starting high on the left, passing through (0,3)(0, 3), and getting closer and closer to the x-axis as you move right – then you've got a good visual confirmation. The process of checking if an ordered pair (x,y)(x, y) lies on the graph is essentially asking: