2.1-2.2 Vocabulary and postulates

Conditional statement

p ➡ q if p than q

converse

q ➡ p if q than p

inverse

˜ p ➡ ˜q if not p than not q

contrapositive

˜q ➡ ˜p if not q than not p

biconditional-only happens if conditional statement and converse statement are true

p ↔ q p if and only if q

inductive reasoning

follows patterns

deductive reasoning

follows rules

law of detachment

if p then q
if p is true - happens when q is true

law of syllogen

if a=b, b=c, then a=c

counterexample

example disprove conclusions

2.1 two point postulate

if •a •b then ↔ a and b

2.2 line point postulate

if ↔️ then ↔ a and b

2.3 line intersection postulate

if 2 lines intersect it’s at 3 points

2.4 three point postulate

if •x •y •z then plane xyz

2.5 plane point postulate

if plane then plane xyz

2.6 plane line postulate

if plane and a line then plane and a line running through plane

2.7 plane intersection postulate

if two planes intersect then it is a plane intersection postulate