Define the 5 neighbourhood of a.

1.	Define the 5 neighbourhood of a.
Answer» If a ∈ R and δ is non-negative real number, then the open interval (a – δ, a + δ) is called δ neighbourhood of a. It is denoted by N (a, δ). Thus, N (a, δ) = {x\|(a – δ) < x < (a + δ), x ∈ R} = {x\| \|x – a\| < δ. x ∈ R}

Answer»

If a ∈ R and δ is non-negative real number, then the open interval (a – δ, a + δ) is called δ neighbourhood of a. It is denoted by N (a, δ). Thus,

N (a, δ) = {x|(a – δ) < x < (a + δ), x ∈ R}
= {x| |x – a| < δ. x ∈ R}

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