GEOMETRIA

Academic Year 2025/2026 - Teacher: Antonio CAUSA

Expected Learning Outcomes

The aim of this course is to provide the fundamental concepts and tools for a first introduction to Linear Algebra and Analytic Geometry. Topics include the properties of matrices, systems of linear equations, and vector spaces, with particular attention to the computation of real eigenvalues and eigenvectors. The course also covers the classification of plane conics and quadric surfaces, using invariants and polar coordinates as key techniques. Throughout the course, students will work on problems analogous to those proposed in the final examination, thereby consolidating both their theoretical understanding and problem-solving skills.


Knowledge and Understanding
Understand statements and proofs of fundamental theorems in algebra, analytic geometry, linear algebra, and the geometry of curves.
Demonstrate mathematical skills in reasoning, manipulation, and computation.
Solve mathematical problems which, although not standard, are of a similar nature to those already familiar to students.
Applying Knowledge and Understanding
Prove known mathematical results using techniques different from those already studied.
Construct rigorous proofs.
Develop simple examples.
These skills will be acquired through interactive teaching: students will continuously test their own knowledge, working independently or in collaboration within small groups on new problems proposed during lectures, tutorials, and support sessions.
Making Judgements
Develop an informed autonomy of judgement in evaluating and interpreting the solution of geometry problems.
Construct and develop logical arguments with a clear identification of assumptions and conclusions.
Recognize correct proofs and identify fallacious reasoning.
These objectives will be pursued through exercises carried out during the course and in support activities for the Geometry course, providing opportunities for students to independently develop decision-making and evaluative skills. Interactive teaching methods will ensure that students in the physics program constantly test their understanding, both individually and collaboratively, through problem-solving activities proposed during lectures and support sessions.
Communication Skills
Communicate information, ideas, problems, solutions, and conclusions clearly and unambiguously.
Present, orally and in writing, the most important theorems of linear algebra and analytic geometry in a clear and comprehensible manner.
Work effectively in groups while maintaining defined levels of autonomy.
To achieve these skills, students will engage in frequent opportunities for written work, discussion, and evaluation. The final exam will also provide an additional opportunity to demonstrate the ability to analyze, elaborate, and communicate the work carried out.
Learning Skills
Develop the competencies needed to pursue further studies with a high degree of autonomy.
Acquire learning abilities and a solid standard of knowledge and skills sufficient for admission to courses at the master’s level in physics.
Cultivate a flexible mindset, enabling quick integration into working environments and the ability to adapt easily to new problems.
These learning skills will be developed throughout the degree program, with particular emphasis on the hours dedicated to independent study.

Course Structure

Frontal lectures and classroom exercise. The teaching approach is a traditional one. The program offers personal feedback and attention from tutors in order to help students in their studies. 

49 hours of lectures and 30 hours of exercises are scheduled, corresponding to 9 ECTS credits.
If the course is delivered in a blended or distance-learning format, necessary adjustments may be introduced to ensure that the program described in the syllabus is fully covered.
Attendance is normally mandatory (please refer to the Academic Regulations of the Degree Program for any exceptions).

Should teaching be carried out in mixed mode or remotely, it may be necessary to introduce changes with respect to previous statements, in line with the programme planned and outlined in the syllabus.
  
Learning assessment may also be carried out on line, should the conditions require it.
 

Required Prerequisites

Prerequisites
The prerequisites are those required for admission to the degree program. A knowledge of the fundamentals of Euclidean geometry in the plane, including the main definitions and theorems, can facilitate a smoother understanding of the curricular lectures. Similarly, a basic familiarity with the concepts of Cartesian geometry—although they will be thoroughly covered during the course—will support the student throughout the lessons. Basic skills in literal calculus and algebraic equations are also expected.
Elementary Euclidean Geometry. Cartesian geometry. Basic knowledge of polynomial algebra.

Attendance of Lessons

Attendance at lessons is strongly recommended. Students are also advised to participate actively in the lessons, to review the topics of the lesson and to undertake the verification exercises that are proposed during the lesson.


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Detailed Course Content

Linear Algebra

  1. Matrices over a field. Matrices addition, scalar multiplication, matrix multiplication (or product). Diagonal, triangular, scalar, symmetric, skew-simmetric matrices and transpose of matrix.
  2. Vector spaces and their properties over R. Examples: R[x], Rn, Rm,n.. Subspaces. Intersection and sum of vector spaces. Direct sum. Linear combinations. Span, Linear Independence and dependence,Finitely generated vector spaces, Base, Dimension. Steinitz’s Lemma *, Grassmann’s formulas*.
  3. Determinants and their properties. Theorems of Binet*,Laplace I*, Laplace II*, Adjunct matrix, Inverse, Rank and Reduction of a matrix. Theorem of Kronecker*. Systems of linear equations. Rouchè-Capelli‘s rule, Cramer’s rule. Solving systems of linear equations.
  4. Linear maps between vector spaces and their properties. Kernel and image of a linear map. Injective, surjective maps and isomorphisms. Study of linear maps. Matrices associated to linear maps. Change of base matrix. Similar matrices.
  5. Eigenvalues, Eigenvectors and Eigenspaces of a matrix. Characteristic polynomial. Dimension of an eigenspace. Relation between Algebraic multiplicity and geometric multiplicity. Linear Independence of the eigenvectors. Diagonalizable linear maps and diagonalization of a matrix.

Geometry

I) Euclidean (geometric) vectors and their properties. Scalar multiplication, dot (or scalar) product, wedge (or cross) product.

II) Cartesian coordinates. Points, lines , Homogeneous coordinates, Points at infinity (Improper Points), Parallel and orthogonal Lines. Slope of a line. Distances from a point to a line. Pencil of lines. Planes in The space. Coplanar and Skew lines. Pencil of Planes. Angles between lines and planes. Distance from a point to a plane and from a point to a line in the space.

III) Conics and their associated matrices. Orthogonal Invariants. Canonical reduction of a conic*. Irreducible and degenerate conics. Rank of its associated matrix. Discriminant of a conic. Parabolas, Ellipses, Hyperbolas: equations, focus, eccentricity, directrix, semi-maior axis, center. Circumferences, Tangents, and pencils of conics.

IV) Quadrics and its associated matrix. Nondegenerate, degenerate and singular quadric surfaces. Cones and cylinders. Classification.

Textbook Information

1) S. Giuffrida, A.Ragusa, Corso di Algebra Lineare, Ed. Il Cigno G.Galilei, Roma 1998 (Linear Algebra).

2) G. Paxia, Lezioni di Geometria, Spazio Libri, Catania, 2005 (Geometry) available at www.giuseppepaxia.com

3) D. Margalit , J. Rabinoff, Interactive linear algebra, available at https://textbooks.math.gatech.edu/ila/

Course Planning

 SubjectsText References
1Linear spaces: definition and basic properties. Examples: R^n, R^m,n, R[X]. Intersection and sum of subspaces. Generators of a linear space.  Linear dependence. Bases of a linear space. Dimension of a linear space. Grassmann formula.D. Margalit , J. Rabinoff, Interactive linear algebra, available at https://textbooks.math.gatech.edu/ila/
21 Matrices with coefficients in a field. Matrix algebra: sum, scalar product, dot product. Basic properties of the ring of square matrices. Triangular and diagonal matrices, symmetric and antysimmetric matrices. Operations on matrices.D. Margalit , J. Rabinoff, Interactive linear algebra, available at https://textbooks.math.gatech.edu/ila/
3Determinant of a matrix. Binet and Laplace theorems on determinants. Inverse of matrix. Gaussian elimination: reduced row echelon form. Rank of a matrix. Kroneker theorem. Linear equations. Cramer theorem, Rouchè theorem. Homogeneous linear systems of equations.D. Margalit , J. Rabinoff, Interactive linear algebra, available at https://textbooks.math.gatech.edu/ila/
4Vector spaces homomorphisms. Null space and range space. Injectivity and surjectivity. Rank-nullity theorem. Matrix representation of a linear transformation. Matrix similarity.3) D. Margalit , J. Rabinoff, Interactive linear algebra, available at https://textbooks.math.gatech.edu/ila/
5Endomorphism and their eigenvalues and eigenvectors. Characteristic polynomial of a matrix. Eigenspaces. Endomorphisms and diagonalization. Diagonalizable matrices.D. Margalit , J. Rabinoff, Interactive linear algebra, available at https://textbooks.math.gatech.edu/ila/
6Geometric vectors and basic operations with geometric vectors: dot product, cross product, triple product.D. Margalit , J. Rabinoff, Interactive linear algebra, available at https://textbooks.math.gatech.edu/ila/
7Cartesian coordinates in plane and space. Orthogonality and parallelism.Planes and lines in space. G. Paxia, Lezioni di Geometria, Spazio Libri, Catania, 2005 
8Classification of affine conics. Quadratic forms. Canonical forms of a conic. Tangent lines to a conic.G. Paxia, Lezioni di Geometria, Spazio Libri, Catania, 2005 
9Quadrics in affine and projective spaces. Classification of quadrics. Double points of a quadric.G. Paxia, Lezioni di Geometria, Spazio Libri, Catania, 2005 

Learning Assessment

Learning Assessment Procedures

To assess students' knowledge and skills, students are requested to attend a written exam and an oral exam.

Examples of frequently asked questions and / or exercises

Linear algebra

Linear spaces: definition and basic properties. Linear independence, bases of a vector space. Dimension of a vector space. Coordinates of a vector. Linear transformations: definition and basic properties. Matrix associated to a linear transformation. rank-nullity theorem. Eigenvalues and eigenvectors. Spaces endowed  with a scalar product. Cauchy-Schwartz inequality. The Spectral theorem. 

Geometry

Lines and planes in space. Orthogonality between lines and/or planes. Conics and quadrics: classification, tangent lines. Double points of a quadric.