Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
8. Conic Sections
Introduction to Conic Sections
Problem 52
Textbook Question
Identify each equation without completing the square.
9x2+25y2−54x−200y+256=0

1
Recognize the given equation: \(9x^2 + 25y^2 - 54x - 200y + 256 = 0\). This is a quadratic equation in two variables, which suggests it might represent a conic section.
Identify the coefficients of \(x^2\) and \(y^2\). Here, \(9\) is the coefficient of \(x^2\) and \(25\) is the coefficient of \(y^2\). Since both coefficients are positive and different, the equation represents an ellipse.
To confirm it's an ellipse, check that the equation is in the general form of a conic section: \(Ax^2 + By^2 + Cx + Dy + E = 0\). Here, \(A = 9\), \(B = 25\), \(C = -54\), \(D = -200\), and \(E = 256\).
Since \(A\) and \(B\) are both positive and \(A \neq B\), this confirms the equation is an ellipse.
Note that completing the square is not necessary to identify the type of conic section, but it would be required to find the center and axes of the ellipse.
Recommended similar problem, with video answer:

This video solution was recommended by our tutors as helpful for the problem above
Video duration:
2mPlay a video:
Was this helpful?
Watch next
Master Geometries from Conic Sections with a bite sized video explanation from Nick Kaneko
Start learningRelated Videos
Related Practice