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Let A = {a + 5b : a, b ∈ Z}. Check whether the usual multiplication is a binary operation on A - Mathematics

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प्रश्न

Let A = {a + `sqrt(5)`b : a, b ∈ Z}. Check whether the usual multiplication is a binary operation on A

बेरीज

उत्तर

Let A = `"a" + sqrt(5) "b"` and B = `"C" + sqrt(5)"d"`

Where a, b, c, d ∈ M.

Now A * B = `("a" + sqrt(5)"b")("c" + sqrt(5)"b")`

= `"ac" + sqrt(5)"ad" + sqrt(5)"bc" + sqrt(5)"b" sqrt(5)"d"`

= (ac + 5bd) + `sqrt(5)`(ad+ bc) ∈ A

Where a, b, c, d ∈ Z

So * is a binary operation.

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पाठ 12: Discrete Mathematics - Exercise 12.1 [पृष्ठ २३५]

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सामाचीर कलवी Mathematics - Volume 1 and 2 [English] Class 12 TN Board
पाठ 12 Discrete Mathematics
Exercise 12.1 | Q 4 | पृष्ठ २३५

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