Vectors and linear combinations
Addition and scalar multiplication drawn as arrows in the plane, and the equivalence between a linear combination and a consistent augmented system.
Understanding Linear Algebra, Vectors and linear combinations
6 exercises
Activity 2.1.3
Given the vectors , can be expressed as a linear combination of , , and ? Rephrase this question by writing a linear system for the weights , , and and use the Sage cell below to answer this question.
Consider the following linear system. Identify vectors , , , and such that the question "Is this linear system consistent?" is equivalent to the question "Can be expressed as a linear…
Exercise 3
Consider the vectors
Find the linear combination with weights , , and .
Can you write the vector as a linear combination of , , and ? If so, describe all the ways in which you can do so.
Can you write the vector as a linear combination using just the first two vectors ? If so, describe all the ways in which you can do so.
Can you write as a linear combination of and ? If so, in how…
Exercise 4
Nutritional information about a breakfast cereal is printed on the box. For instance, one serving of Frosted Flakes has 111 calories, 140 milligrams of sodium, and 1.2 grams of protein. We may represent this as a vector . One serving of Cocoa Puffs has 120 calories, 105 milligrams of sodium, and 1.0 grams of protein.
Write the vector describing the nutritional content of Cocoa Puffs.
Suppose you eat…
Exercise 5
Consider the vectors
Can you express the vector as a linear combination of , , and ? If so, describe all the ways in which you can do so.
Can you express the vector as a linear combination of , , and ? If so, describe all the ways in which you can do so.
Show that can be written as a linear combination of and .
Explain why any linear combination of , , and , can be rewritten as a l…
Exercise 6
Consider the vectors For what value(s) of , if any, can the vector be written as a linear combination of and ?
Exercise 7
Determine whether the following statements are true or false and provide a justification for your response.
Given two vectors and , the vector is a linear combination of and .
Suppose is a collection of -dimensional vectors and that the matrix has a pivot position in every row. If is any -dimensional vector, then can be written as a linear combination of .
Suppose is a collection…
Adapted from Understanding Linear Algebra © 2023 David Austin. Licensed under CC BY 4.0. Source: Understanding Linear Algebra. Imported at revision 3e6dced.