Operations on Sets

Example 1:

Let $A=\left\{1,2,3,4\right\}$ and let $B=\left\{3,4,5,6\right\}$ .

Then:

$A\cap B=\left\{3,4\right\}$

$A\cup B=\left\{1,2,3,4,5,6\right\}$

$A-B=\left\{1,2\right\}$

$A^C=\left\{\text{all real numbers except }1,2,3\text{ and }4\right\}$

Example 2:

Let $A=\left\{y,z\right\}$ and let $B=\left\{x,y,z\right\}$ .

Then:

$\begin{array}{l}A\cap B=\left\{y,z\right\}\\ A\cup B=\left\{x,y,z\right\}\\ A-B=\varnothing \\ A^C=\left\{\text{everything except }y\text{ and }z\right\}\end{array}$