Question

If $A=\left\{\right(x,y):x^2+y^2\le 1x,y\in R\}$ and $B=\left\{\right(x,y):x^2+y^2\le 16x,y\in R\}$ , then

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

Answer 1

The correct option is C $A-B=\varphi$

Set $A$ represents all the points lying inside or on the circle centred at the origin and radius $1$ and set $B$ represents all the points lying inside or on the circle centred at the origin and radius $4$
As both the circles are concentric so the set $A$ is completely contained in $B$
$\Rightarrow A-B=\varphi$
So option $C$ is correct