MATH127 Lecture Notes - Hyperbola
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To say x is an integer, we write x , = { 0, 1, 2, ) The natural numbers are the set of all the integers: n, n = { 1, 2, 3, } The set of all rational numbers is denoted = { p/q | p , q , and q 0 } The set of all real numbers is . The union of a and b, denoted as a b, is the set of everything in a and everything in b. A b = { x | x a or x b } Let a = { 1, 2, 3 } and b = { 2, 4, 6 }, then a b = { 2 } and a b = {1, 2, 3, 4, 6} remove duplicates. The answer is denoted as: x ( 5/4, ) or { x | x > 5/4 } Solve: x - 2x - 15 0 (x - 5)(x +3) 0.