Question

A={X:X in a integer and x^2-1=0} write in roster form
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Answer 1

Given a set A in set builder form,

$\longrightarrow A=\{x:x\ is an integer and \ x^2-1=0\}$

We need to write it in roster form.

Roster form is the notation of a set by representing all of its elements inside curly brackets, separated by commas.

Here the condition is that $x$ is an integer such that $x^2-1=0.$ Let us solve the equation.

$\longrightarrow x^2-1=0$

$\longrightarrow x=\pm 1$

Here both 1 and -1 are integers. So both are elements of A. No other elements are being in A.

Hence The set A in roster form is,

$\longrightarrow\underline{\underline{A=\{-1,\ 1\}}}$