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Question
If `A = ((a, 0, 0),(0, a, 0),(0, 0, a))`, then An equal to ______.
Options
`((a^n, 0, 0),(0, a^n, 0),(0, 0, a^n))`
`((a, 0, 0),(0, a^n, 0),(0, 0, a))`
`((a^n, 0, 0),(0, a, 0),(0, 0, a^n))`
`((na, 0, 0),(0, na, 0),(0, 0, a^n))`
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Solution
If `A = ((a, 0, 0),(0, a, 0),(0, 0, a))`, then An equal to `underlinebb(((a^n, 0, 0),(0, a^n, 0),(0, 0, a^n)))`.
Explanation:
Given: `A = ((a, 0, 0),(0, a, 0),(0, 0, a))`
The matrix A is a scalar multiple of the identity matrix, which can be written as A = aI, where `I = ((1, 0, 0),(0, 1, 0),(0, 0, 1))` is the identity matrix.
To find An, we can raise this expression to the power of n:
An = (aI)n
Using the property of matrix multiplication that (kI)n = knIn = knI, where k is a scalar:
An = anI
`A^n = a^n((1, 0, 0),(0, 1, 0),(0, 0, 1))`
`A^n = ((a^n, 0, 0),(0, a^n, 0),(0, 0, a^n))`
