Unit 1 establishes the bedrock of advanced algebra by uniting relations, sets, and functions. An ordered pair (a, b) maintains strict directional integrity: (a, b) = (x, y) <=> a = x and b = y. The Cartesian product X x Y generates all ordered pairs from set X to set Y with cardinality n(X x Y) = n(X) * n(Y). Furthermore, the orthogonal coordinate plane allocates points into four distinct quadrants based on sign pairings (+/-, +/-), with points on the x-axis having y = 0 and points on the y-axis having x = 0.
Quick Concept Check
Question: What is the cardinality of X x Y if n(X) = 4 and n(Y) = 6? What coordinate is 0 on the x-axis?
Key Answer: n(X x Y) = 4 * 6 = 24. On the x-axis, the y-coordinate is 0.
A relation R from X to Y graduates to a (Function) if every element of domain X appears as a first projection exactly once. The set of inputs X is the (Domain), the target set Y is the (Codomain), and the set of actual outputs (images) is the (Range), which is invariably a subset of the Codomain: [Range subset_of Codomain]. In graphical terms, every domain element in an arrow diagram possesses exactly one outgoing arrow, and every vertical line on a Cartesian grid meets the graph at a single point.
Quick Concept Check
Question: What is the relationship between Range and Codomain in any function?
Key Answer: The Range is always a subset of the Codomain (Range subset_of Codomain).
Polynomial functions f: R -> R require natural number exponents for all variables. They are classified by their highest power: Constant (Degree 0, horizontal line parallel to x-axis), Linear (Degree 1, line intersecting y-axis at (0, b) and x-axis at (-b/a, 0)), and Quadratic (Degree 2, parabola). If a linear function has b = 0 [f(x) = ax], its straight line passes through the Origin (0, 0), exhibiting direct proportionality.
Quick Concept Check
Question: Where does the line f(x) = 3x - 12 intersect the x-axis and y-axis?
Key Answer: Y-intercept is (0, -12). X-intercept: 3x - 12 = 0 => x = 4 => (4, 0).
The quadratic function f(x) = ax^2 + bx + c produces a Parabola with vertex (h, k) where h = -b/(2a) and k = f(h). The axis of symmetry is strictly stated as the equation [x = h], while the extreme value is [y = k] (minimum if a > 0, maximum if a < 0). Achieving full marks in national exams demands writing equations completely, labeling graph axes clearly, and verifying arithmetic operations systematically.
Quick Concept Check
Question: What two key features are extracted from the vertex (h, k) of a quadratic curve?
Key Answer: 1. Equation of the axis of symmetry: x = h. 2. Minimum or maximum value of the function: y = k.