Question

If $A=\left\{\right(x,y):x^2+y^2\le 1;x,y\in R\}$ and $B=\left\{\right(x,y):x^2+y^2\ge 4;x,y\in R\}$, then

• A. $A-B=\varphi$
• B. $B-A=\varphi$
• C. $A\cap B\ne \varphi$
• D. $A\cap B=\varphi$

Answer 1

The correct option is D $A\cap B=\varphi$

The graph for $A=\left\{\right(x,y):x^2+y^2\le 1;x,y\in R\}$ and $B=\left\{\right(x,y):x^2+y^2\ge 4;x,y\in R\}$ is

There is no common region of $A$ and $B$
Hence, $A\cap B=\varphi$