Chapter 11: Problem 9
Find the center, foci, vertices, and asymptotes of the hyperbola. Then sketch the graph. $$ \frac{(x+1)^{2}}{9}-\frac{(y-3)^{2}}{16}=1 $$
Short Answer
Expert verified
Center: (-1, 3); Vertices: (2, 3), (-4, 3); Foci: (4, 3), (-6, 3); Asymptotes: y = 3 ± 4/3(x + 1).
Step by step solution
01
Standard Form Identification
The given equation is \( \frac{(x+1)^{2}}{9}-\frac{(y-3)^{2}}{16}=1 \). This is the standard form of a horizontal hyperbola: \( \frac{(x-h)^2}{a^2} - \frac{(y-k)^2}{b^2} = 1 \), where the center is \((h, k)\), \(a^2 = 9\), and \(b^2 = 16\).
02
Find the Center
From the standard form, \( (h, k) = (-1, 3) \). This is derived from \((x+1)^2\) and \((y-3)^2\).
03
Calculate Vertices
For a horizontal hyperbola, the vertices are located at \((h \pm a, k)\). Here, \(a = \sqrt{9} = 3\). Therefore, the vertices are \((-1 \pm 3, 3)\), or \((2, 3)\) and \((-4, 3)\).
04
Identify Foci
Foci are calculated using \(c^2 = a^2 + b^2\). So, \(c^2 = 9 + 16 = 25 \), hence \(c = 5\). The foci are \((h \pm c, k)\), which are \((-1 \pm 5, 3)\), or \((4, 3)\) and \((-6, 3)\).
05
Determine Asymptotes
Asymptotes for a horizontal hyperbola are given by \(y = k \pm \frac{b}{a}(x - h)\). Substituting \(a = 3\), \(b = 4\), \(h = -1\), and \(k = 3\), the asymptotes are \(y = 3 \pm \frac{4}{3}(x + 1)\).
06
Sketch the Graph
Using the center \((-1, 3)\), plot the vertices \((2, 3)\) and \((-4, 3)\), and the foci \((4, 3)\) and \((-6, 3)\). Draw the rectangle bounded by \(a\) and \(b\) to guide the hyperbola's direction, and sketch the asymptotes \(y = 3 \pm \frac{4}{3}(x + 1)\). Finally, draw the hyperbola opening left and right, centered at \((-1, 3)\).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Horizontal Hyperbola
A horizontal hyperbola is a specific type of hyperbola where the transverse axis runs horizontally. This simply means that the opening of the hyperbola is left and right from its center.
For a hyperbola to be horizontal, its standard equation must have the form:
For a hyperbola to be horizontal, its standard equation must have the form:
- \( \frac{(x-h)^2}{a^2} - \frac{(y-k)^2}{b^2} = 1 \)
- \((h, k)\) represents the center of the hyperbola. In our exercise, these values are \( (-1, 3) \).
- The positive term in the equation (\( (x-h)^2 \)) indicates that this is a horizontal hyperbola.
- \( a \) and \( b \) are the distances related to the shape and orientation of the hyperbola.
Vertices
The vertices of a hyperbola are critical points that determine its shape and help in plotting the graph.
For a horizontal hyperbola, the vertices are located at a fixed distance from the center along the horizontal axis.
This distance is given by the value \( a \), where \( a = \sqrt{9} = 3 \) in our case.
Using the center \((h, k) = (-1, 3)\), the vertices can be calculated as follows:
For a horizontal hyperbola, the vertices are located at a fixed distance from the center along the horizontal axis.
This distance is given by the value \( a \), where \( a = \sqrt{9} = 3 \) in our case.
Using the center \((h, k) = (-1, 3)\), the vertices can be calculated as follows:
- \((h + a, k) = (-1 + 3, 3) = (2, 3)\)
- \((h - a, k) = (-1 - 3, 3) = (-4, 3)\)
Foci
Foci are two important points on the major axis of a hyperbola that help in accurately defining its shape. They lie further out from the center than the vertices.
To locate the foci, we use the relationship \( c^2 = a^2 + b^2 \). From the problem:
To locate the foci, we use the relationship \( c^2 = a^2 + b^2 \). From the problem:
- \( a^2 = 9 \) and \( b^2 = 16 \)
- Thus, \( c^2 = 9 + 16 = 25 \) => \( c = 5 \)
- \((h + c, k) = (-1 + 5, 3) = (4, 3)\)
- \((h - c, k) = (-1 - 5, 3) = (-6, 3)\)
Asymptotes
Asymptotes are lines that the branches of the hyperbola approach but never touch. They guide the shape of the hyperbola and give a sense of its openness.
For a horizontal hyperbola, asymptotes are given by the formula:
For a horizontal hyperbola, asymptotes are given by the formula:
- \( y = k \pm \frac{b}{a}(x - h) \)
- \( k = 3 \), \( h = -1 \), \( b = 4 \), \( a = 3 \)
- The equations become:
- \( y = 3 \pm \frac{4}{3}(x + 1) \)
- \( y = 3 + \frac{4}{3}(x + 1) \)
- \( y = 3 - \frac{4}{3}(x + 1) \)