Linear Algebra Concepts and Applications

This video tutorial introduces homogeneous systems of linear equations, explaining that such systems have either a trivial solution or an infinite number of solutions. It demonstrates solving these systems using augmented matrices and row operations. Two examples are provided: one with a trivial solution and another with parametric solutions, highlighting the concept of free variables and their role in determining the number of solutions.

What is a key characteristic of a homogeneous system of linear equations?

• The constant term is non-zero.

• The constant term is zero.

• It has no solutions.

• It always has a unique solution.

Under what condition does a homogeneous system have infinite solutions?

• When the number of equations is greater than the number of variables.

• When the number of variables is greater than the number of equations.

• When all variables are zero.

• When the number of variables is equal to the number of equations.

In the first example, what is the result when x sub 2 equals zero?

• x sub 1 equals three.

• x sub 1 equals two.

• x sub 1 equals one.

• x sub 1 equals zero.

What operation is performed to obtain a zero in the augmented matrix in the first example?

• Multiply row two by -3 and add to row one

• Multiply row one by -3 and add to row two

• Add row one to row two

• Subtract row two from row one

How many free variables are there in the second example?

• One

• Zero

• Two

• Three

What is the result of multiplying row two by -1/3 in the second example?

• The second row becomes 1, 1, 4, 0

• The second row becomes 0, 1, -4, 0

• The second row becomes 1, 0, -4, 0

• The second row becomes 0, -1, 4, 0

What is the parametric representation of x sub 3 in the second example?

• x sub 3 equals zero

• x sub 3 equals one

• x sub 3 equals T

• x sub 3 equals 4T

What does the parametric representation help express in a system with infinite solutions?

• The unique solution

• The trivial solution

• All possible solutions

• No solutions

In the second example, what is the value of x sub 2 when x sub 3 equals T?

• x sub 2 equals T

• x sub 2 equals 2T

• x sub 2 equals 3T

• x sub 2 equals 4T

What is the final expression for x sub 1 in terms of T in the second example?

• x sub 1 equals 8T

• x sub 1 equals 3T

• x sub 1 equals -5T

• x sub 1 equals 5T