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Ch. 7 - Conic Sections
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514당신이 사용하는 게 아니라요?교과서 변경
8장, 문제 11

Graph each ellipse and locate the foci. x² = 1 – 4y²

검증된 단계별 안내
1
Rewrite the given equation \(x^2 = 1 - 4y^2\) to the standard form of an ellipse equation. Start by moving all terms to one side: \(x^2 + 4y^2 = 1\).
Divide both sides of the equation by 1 to express it in the form \(\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1\). Here, it becomes \(\frac{x^2}{1} + \frac{y^2}{\frac{1}{4}} = 1\).
Identify the values of \(a^2\) and \(b^2\). From the equation, \(a^2 = 1\) and \(b^2 = \frac{1}{4}\). Since \(a^2 > b^2\), the major axis is along the x-axis.
Calculate the focal distance \(c\) using the relationship \(c^2 = a^2 - b^2\). Substitute the values to get \(c^2 = 1 - \frac{1}{4}\).
Locate the foci at points \((\pm c, 0)\) on the x-axis. These points represent the foci of the ellipse. Finally, sketch the ellipse using the intercepts and foci.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
10m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Standard Form of an Ellipse

An ellipse is typically expressed in the form \( \frac{(x-h)^2}{a^2} + \frac{(y-k)^2}{b^2} = 1 \), where \((h,k)\) is the center, and \(a\) and \(b\) are the lengths of the semi-major and semi-minor axes. Understanding how to rewrite the given equation into this form is essential for graphing the ellipse.
추천 영상:
5:12
Graph Ellipses at Origin

Identifying the Orientation of the Ellipse

The ellipse can be oriented horizontally or vertically depending on whether the \(x^2\) or \(y^2\) term is associated with the larger denominator. Recognizing the orientation helps in correctly plotting the ellipse and locating its axes.
추천 영상:
4:50
Graph Ellipses NOT at Origin

Locating the Foci of an Ellipse

The foci are two fixed points inside the ellipse, located along the major axis, found using \( c^2 = |a^2 - b^2| \). Knowing how to calculate \(c\) and place the foci relative to the center is crucial for completing the graph accurately.
추천 영상:
5:30
Foci and Vertices of an Ellipse