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Property

Definition of the inverse

AB=BA=I    B=A1AB = BA = I \iff B = A^{-1}
II
the identity matrix

Two matrices are inverses precisely when their product in both orders is the identity, and the inverse when it exists is unique.

33
questions use it
16
of them past-year
2018–2026
years it has appeared
12%
rated HARD
4
exams
Matrices & Determinants notesOpen all 33 in the paper builder

Used alongside

How often each of these appears in the same solution as this one.

33 questions whose solution uses this

Every one was read individually — a question is here because its solution invokes this, not because the stem mentions it.

Every identity this chapter tests, with its own question set.

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