Question

How do you multiply `(sqrt(a) +sqrt(b))(sqrt(a)-sqrt(b))`?

Answer 1

You can treat it like Difference of Two Squares

`(a + b)(a - b) = a^2 - b^2`

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`(root 2 a + root 2 b)(root 2 a - root 2 b)`

`=> root 2 (a^2) - root 2 (b^2)`
`=> a - b`