1. Day 2: Fnct notation, evaluating fnct, finding domain from equation
NOTATION
A function may be specified by a rule or an equation.
Notation:
(1) y = x2 + 1 y equals x squared plus one
(2) {(x, y) y = x2 + 1} set of all points (x, y) such that
y = x2 + 1
(3) f(x) = x2 + 1 f of x equals x squared plus one
(4) f: f(x) = x2 + 1 function f maps x to x2 + 1
f
(5) x x2 + 1 x gets mapped to x2 + 1 through
function f
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2. EVALUATING FUNCTIONS
Evaluation = Substitution
A: Evaluate x2 + 3x 1
when x = 2
B: If f (x) = x2 + 3x 1,
evaluate f(2)
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