Determinants Matrices Question 73

Question: Consider the following statements:
  1. If det $ A=0, $ then det $ (adjA)=0 $
  2. If A is non- singular, then $ \det ({A^{-1}})={{(\det A)}^{-1}} $

Options:

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

Show Answer

Answer:

Correct Answer: C

Solution:

  • [c] We know that, adj A and A has same value of determinant, if det A = 0, then det (adj A) = 0 So, statement (1) is correct. Also if A is a matrix the determinant of $ {A^{-1}} $ equals inverse of determinant A, so, det $ ({A^{-1}}) $

$ ={{(detA)}^{-1}} $ , if A is non-singular; statement 2 is correct. Thus both (1) and (2) are correct.