High School

Let \( T \) be the linear transformation whose standard matrix is \(\begin{bmatrix} 0 & 2 \\ -1 & 3 \end{bmatrix}\).

Which of the following statements are true?

(i) \( T \) maps \(\mathbb{R}^3\) onto \(\mathbb{R}\)

(ii) \( T \) maps \(\mathbb{R}\) onto \(\mathbb{R}^3\)

(iii) \( T \) is onto

(iv) \( T \) is one-to-one

A. (i) and (iii) only

B. (i) and (iv) only

C. (ii) and (iv) only

D. (iii) and (i) only

E. (ii), (iii), and (iv) only

Answer :

To determine which of the given statements are true, let's analyze the properties of the linear transformation T represented by the standard matrix:

0 2

-1 3

(i) T maps R^3 onto R:

For T to map R^3 onto R, every element in R must have a pre-image in R^3 under T. In this case, since the second column of the matrix contains nonzero entries, we can conclude that T maps R^3 onto R. Therefore, statement (i) is true.

(ii) T maps R onto R^3:

For T to map R onto R^3, every element in R^3 must have a pre-image in R under T. Since the matrix does not have a third column, we cannot conclude that every element in R^3 has a pre-image in R. Therefore, statement (ii) is false.

(iii) T is onto:

A linear transformation T is onto if and only if its range equals the codomain. In this case, since the second column of the matrix is nonzero, the range of T is all of R. Therefore, T is onto. Statement (iii) is true.

(iv) T is one-to-one:

A linear transformation T is one-to-one if and only if its null space contains only the zero vector. To determine this, we can find the null space of the matrix. Solving the equation T(x) = 0, we get:

0x + 2y - z = 0

-x + 3*y = 0

From the second equation, we can express x in terms of y: x = 3y. Substituting this into the first equation, we get:

0 + 2y - z = 0

2y = z

This implies that z must be a multiple of 2y. Therefore, the null space of T contains nonzero vectors, indicating that T is not one-to-one. Statement (iv) is false.

Based on the analysis above, the correct answer is:

A. (i) and (iii) only.

Learn more about linear transformation here: brainly.com/question/32386535

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