Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Determinants

Question:

If A = \(\begin{bmatrix}4 & 10\\2 & 1 \end{bmatrix}\), then what is the value of |\(3 { A }^{ T } \)|?

Options:

48

144

-48

-144

Correct Answer:

-144

Explanation:

If Matrix A has size a × a and k is a constant, then |kA| = \( { k }^{ a } \) |A|

Then, |\(3 { A }^{ T } \)| = \( { 3 }^{ 2 } \) |\( { A }^{ T } \)|

                                       = \( { 3 }^{ 2 } \) |A |

Because |\( { A }^{ T } \) = |A |

|\(3 { A }^{ T } \)| = 9 |A |

And |A | = -16

So, |\(3 { A }^{ T } \)| = -144