Chapter 4: Problem 7
Find the \(x\) -and \(y\) -intercepts of the rational function. \(t(x)=\frac{x^{2}-x-2}{x-6}\)
Short Answer
Expert verified
The x-intercepts are x = 2 and x = -1; the y-intercept is (0, \(\frac{1}{3}\)).
Step by step solution
01
Identify the Rational Function
We are given the rational function \( t(x) = \frac{x^{2} - x - 2}{x - 6} \). The goal is to find the \( x \)-intercepts and \( y \)-intercepts of this function.
02
Find the X-Intercepts
The \( x \)-intercepts occur where \( t(x) = 0 \). This means we set the numerator equal to zero and solve the quadratic equation: \[ x^2 - x - 2 = 0 \] Factoring or using the quadratic formula gives:\[ (x - 2)(x + 1) = 0 \] Thus, the solutions are \( x = 2 \) and \( x = -1 \). These are the \( x \)-intercepts.
03
Find the Y-Intercept
The \( y \)-intercept is found by evaluating \( t(0) \), which means setting \( x = 0 \). We substitute \( x = 0 \) into the function:\[ t(0) = \frac{0^2 - 0 - 2}{0 - 6} = \frac{-2}{-6} = \frac{1}{3} \]Thus, the \( y \)-intercept is \( \left(0, \frac{1}{3}\right) \).
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
x-intercepts
X-intercepts are a crucial part of understanding the behavior of a graph. They represent the points where a graph crosses the x-axis. In simpler terms, these are the values of \( x \) where the function equals zero. For rational functions, x-intercepts are found by setting the numerator equal to zero.
In the given function, \( t(x) = \frac{x^2 - x - 2}{x-6} \), we focus on the numerator \( x^2 - x - 2 \). To find the x-intercepts, solve \( x^2 - x - 2 = 0 \). Once factored, it becomes \( (x-2)(x+1) = 0 \).
The solutions \( x = 2 \) and \( x = -1 \) indicate the x-intercepts. This means that on the x-axis, the graph crosses or touches the x-axis at these points.
In the given function, \( t(x) = \frac{x^2 - x - 2}{x-6} \), we focus on the numerator \( x^2 - x - 2 \). To find the x-intercepts, solve \( x^2 - x - 2 = 0 \). Once factored, it becomes \( (x-2)(x+1) = 0 \).
The solutions \( x = 2 \) and \( x = -1 \) indicate the x-intercepts. This means that on the x-axis, the graph crosses or touches the x-axis at these points.
y-intercepts
Y-intercepts identify the points where the graph of a function crosses the y-axis. Essentially, this is where the value of \( x \) equals zero.
Finding the y-intercept for a rational function like \( t(x) = \frac{x^2 - x - 2}{x-6} \) is straightforward. Substitute \( x = 0 \) into the function.
After calculation: \( t(0) = \frac{0^2 - 0 - 2}{0-6} = \frac{-2}{-6} = \frac{1}{3} \).
Thus, the graph intersects the y-axis at \( \left( 0, \frac{1}{3} \right) \). This point helps to anchor the graph on the coordinate plane.
Finding the y-intercept for a rational function like \( t(x) = \frac{x^2 - x - 2}{x-6} \) is straightforward. Substitute \( x = 0 \) into the function.
After calculation: \( t(0) = \frac{0^2 - 0 - 2}{0-6} = \frac{-2}{-6} = \frac{1}{3} \).
Thus, the graph intersects the y-axis at \( \left( 0, \frac{1}{3} \right) \). This point helps to anchor the graph on the coordinate plane.
quadratic equation
Quadratic equations often appear when dealing with the numerator of a rational function. These are equations in the form \( ax^2 + bx + c = 0 \). Solving a quadratic equation can provide x-intercepts of the function.
In this exercise, the numerator \( x^2 - x - 2 \) forms a quadratic equation. Solving this involves either factoring or applying the quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \).
Both methods aim to find the roots or solutions for \( x \). Here, we chose to factor: \( (x-2)(x+1) = 0 \). The roots \( x = 2 \) and \( x = -1 \) emerge, representing where the graph touches the x-axis.
In this exercise, the numerator \( x^2 - x - 2 \) forms a quadratic equation. Solving this involves either factoring or applying the quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \).
Both methods aim to find the roots or solutions for \( x \). Here, we chose to factor: \( (x-2)(x+1) = 0 \). The roots \( x = 2 \) and \( x = -1 \) emerge, representing where the graph touches the x-axis.
factoring
Factoring is a technique used to simplify expressions and solve equations more easily. It transforms complex expressions into more manageable products of simpler expressions.
For the quadratic equation in our exercise \( x^2 - x - 2 \), we factor it into \( (x-2)(x+1) \). This conversion transforms a complex polynomial into a simple product, making it easier to find solutions.
Evaluate each factor to zero separately to get the intercepts:
For the quadratic equation in our exercise \( x^2 - x - 2 \), we factor it into \( (x-2)(x+1) \). This conversion transforms a complex polynomial into a simple product, making it easier to find solutions.
Evaluate each factor to zero separately to get the intercepts:
- If \( x-2 = 0 \), then \( x=2 \)
- If \( x+1 = 0 \), then \( x=-1 \)
rational expressions
Rational expressions are fractions made from polynomials. They follow the structure \( \frac{P(x)}{Q(x)} \) where \( P(x) \) and \( Q(x) \) are polynomials. These expressions are prevalent in algebra and calculus.
In the problem, \( t(x) = \frac{x^2 - x - 2}{x-6} \) is our rational function. The numerator is \( x^2 - x - 2 \), and the denominator is \( x-6 \). Simplifying these expressions can provide valuable insights into their behavior, such as identifying intercepts and asymptotes.
Remember not to set a rational expression in its entirety to zero immediately. Instead, focus on the numerator to find zeros, like we did with the x-intercepts. In this process, rational expressions can be quite versatile in representing intricate behaviors of mathematical functions.
In the problem, \( t(x) = \frac{x^2 - x - 2}{x-6} \) is our rational function. The numerator is \( x^2 - x - 2 \), and the denominator is \( x-6 \). Simplifying these expressions can provide valuable insights into their behavior, such as identifying intercepts and asymptotes.
Remember not to set a rational expression in its entirety to zero immediately. Instead, focus on the numerator to find zeros, like we did with the x-intercepts. In this process, rational expressions can be quite versatile in representing intricate behaviors of mathematical functions.