Question

Write the set builder form $A = {-1, 1}$

• A. A = {x : x is a real number}
• B. A = (x : x is an integer)
• C. A = {x : x is a root of the equation $x^2$ = 1}
• D. A = {x : x is a root of the equation $x^2$ + 1 = 0}

Answer 1

Answer: (C)

$-1,1$ are the roots of the equation $x^{2}-1=0$ Hence, set builder form of $A$ can be written as $A=\left\{x: x\right.$ is a root of the equation $\left.x^{2}=1\right\}$