Kevin Halasz

Simon Fraser University
Teaching Assistant

Biography

I am a very recent PhD graduate in combinatorics with a passion for teaching.

Education

Phd Mathematics
Simon Fraser University

Educator Statistics

Numerade tutor for 5 years
63 Students Helped

Topics Covered

Breaking Limits: Unlock Your Potential with Our Expert Solutions
Exploring the World of Derivatives: A Comprehensive Guide
Mastering Matrices: An Introduction to the Fundamentals

Kevin's Textbook Answer Videos

06:52
Elementary Linear Algebra: Applications Version

Find the rank and nullity of the matrix $A$ by reducing it to row echelon form.
(a) $A=\left[\begin{array}{llll}1 & 2 & -1 & 1 \\ 2 & 4 & -2 & 2 \\ 3 & 6 & -3 & 3 \\ 4 & 8 & -4 & 4\end{array}\right]$
(b) $A=\left[\begin{array}{rrrrr}1 & -2 & 2 & 3 & -1 \\ -3 & 6 & -1 & 1 & -7 \\ 2 & -4 & 5 & 8 & -4\end{array}\right]$

Chapter 4: General Vector Spaces
Section 8: Rank, Nullity, and the Fundamental Matrix Spaces
Kevin Halasz
02:05
Linear Algebra and Its Applications

The quadratic $f=x^{2}+4 x y+2 y^{2}$ has a saddle point at the origin, despite the fac that its coefficients are positive. Write $f$ as a difference of two squares.

Chapter 6: Positive Definite Matrices
Section 1: Minima, Maxima, and Saddle Points
Kevin Halasz
07:00
Linear Algebra and Its Applications

Decide for or against the positive definiteness of these matrices, and write out the corresponding $f=x^{T} A x$ :
(a) $\left[\begin{array}{ll}1 & 3 \\ 3 & 5\end{array}\right]$.
(b) $\left[\begin{array}{rr}1 & -1 \\ -1 & 1\end{array}\right]$.
(c) $\left[\begin{array}{ll}2 & 3 \\ 3 & 5\end{array}\right]$.
(d) $\left[\begin{array}{rr}-1 & 2 \\ 2 & -8\end{array}\right]$.
The determinant in (b) is zero; along what line is $f(x, y)=0$ ?

Chapter 6: Positive Definite Matrices
Section 1: Minima, Maxima, and Saddle Points
Kevin Halasz
05:43
Linear Algebra and Its Applications

If a 2 by 2 symmetric matrix passes the tests $a>0, a c>b^{2}$, solve the quadratic equation $\operatorname{det}(A-\lambda I)=0$ and show that both eigenvalues are positive.

Chapter 6: Positive Definite Matrices
Section 1: Minima, Maxima, and Saddle Points
Kevin Halasz
01:39
Linear Algebra and Its Applications

Suppose the positive coefficients $a$ and $c$ dominate $b$ in the sense that $a+c>2 b$. Find an example that has $a c<b^{2}$, so the matrix is not positive definite.

Chapter 6: Positive Definite Matrices
Section 1: Minima, Maxima, and Saddle Points
Kevin Halasz
1 2 3

Kevin's Quick Ask Videos

06:35
Calculus 3

A state senator believes that 25% of all senators on the Financial Committee will strongly support
the tax proposal she wishes to advance. Suppose that this belief is correct and that five senators
are approached at random.
a) What is the probability that at least one of the five will strongly support the proposal?
_________ (1)
b) What is the probability that a majority of the five will strongly support the proposal?
_________ (1)
c) Find the expected value of number of senators that will strongly support the proposal.
_______ (1)
d) Find the standard deviation of number of senators that will strongly support the proposal.

Kevin Halasz
05:08
Intro Stats / AP Statistics

Two firms A and B consider bidding on a costume designing
project for an upcoming new movie, which may or may not be awarded
depending on the amounts of the bids. Firm A submits a bid and the
probability is ¾ that it will get the project provided firm B does
not bid. The probability is ¾ that B will bid, and if it does, the
probability that A will get the project is only 1/3. If A gets the
project, what’s the probability that B did not bid

Kevin Halasz
03:32
Calculus 3

5. Let G be a graph with vertex set V = {1, 2, 3, 4, 5, 6}.
Suppose G has no edges between odd numbered vertices and also no
edges between even numbered vertices.
(a) Draw such a graph with the maximum number of edges.
(b) How many such graphs are there

Kevin Halasz
02:36
Prealgebra

how can I divide 120 by 3.6 ? by hand?

Kevin Halasz
02:27
Prealgebra

One number is 1/2 of another number. The sum of the
two numbers is 21. Find the two numbers. Use a comma to
separate your answers.

Kevin Halasz
02:23
Prealgebra

Find the equation for the line that passes through (4,9) that is
perpendicular to y= (-5/3 x) +5. Give your answer in point-slope
form and leave slope as a fraction.

Kevin Halasz
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