Skip to main content
Ch. 2 - Graphs and Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063당신이 사용하는 게 아니라요?교과서 변경
3장, 문제 41

Describe the graph of each equation as a circle, a point, or nonexistent. If it is a circle, give the center and radius. If it is a point, give the coordinates. x2+y2+4x+14y=-54

검증된 단계별 안내
1
Start by rewriting the given equation: \(x^2 + y^2 + 4x + 14y = -54\).
Group the \(x\) terms and \(y\) terms together: \((x^2 + 4x) + (y^2 + 14y) = -54\).
Complete the square for the \(x\) terms: take half of 4, which is 2, and square it to get 4. Add and subtract 4 inside the equation.
Complete the square for the \(y\) terms: take half of 14, which is 7, and square it to get 49. Add and subtract 49 inside the equation.
Rewrite the equation as perfect square trinomials: \((x + 2)^2 - 4 + (y + 7)^2 - 49 = -54\). Then, combine constants on the right side to find the standard form of the circle equation.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
3m
도움이 되었나요?

주요 개념

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

Standard Form of a Circle Equation

The standard form of a circle's equation is (x - h)^2 + (y - k)^2 = r^2, where (h, k) is the center and r is the radius. Converting a general quadratic equation into this form helps identify the circle's properties.
추천 영상:
5:18
Circles in Standard Form

Completing the Square

Completing the square is a method used to rewrite quadratic expressions as perfect square trinomials. This technique is essential to transform the given equation into the standard form of a circle.
추천 영상:
06:24
Solving Quadratic Equations by Completing the Square

Interpreting the Radius and Existence of the Circle

After rewriting the equation, the radius squared (r^2) must be positive for a circle to exist. If r^2 = 0, the graph is a single point; if r^2 is negative, the graph does not exist in the real plane.
추천 영상:
5:18
Circles in Standard Form