Read: Continue with Section 3.1.
Turn in: 3.16, 3.17, 3.18, 3.19
- Please read Theorem 3.12. It is important and our main way to prove that two sets are equal.
- The sets in 3.17, are intervals of real numbers (see Definition 3.4). Try to write your answers to this exercise in interval notation or using set-builder notation.
- Your goal in 3.19 is to prove $B^c\subseteq A^c$. So, using the hypothesis, you want to prove that for all $x\in B^c$, it follows that $x\in A^c$. As such, your proof should begin with “Let $x\in B^c$” and end with “Thus, $x\in A^c$.”
Extra practice: 3.12, 3.20
