In this unit you will look at quadratics as functions. You will start with the big idea of Grade 11 math: what makes a relation a function, and how to use function notation such as f(3) = 7. You will describe the domain and range of linear and quadratic functions in set notation, and explain the restrictions a real situation puts on them (a snowball can't fly before it is thrown).
Next you will investigate how a, h and k transform the parent function f(x) = x², and sketch g(x) = a(x − h)² + k in under a minute. You will move between the three forms of a quadratic function, standard, vertex and factored, by expanding, completing the square and factoring, verify that the forms are equivalent, describe what each form shows, and sketch from any of them.
In the last part you will collect data that curves like a parabola, find a quadratic model for it by hand and compare it with a regression from technology, and use quadratic functions to solve problems about heights, arches, areas, revenue and profit.
Remember from Grade 10: you graphed quadratic relations, used second differences, met vertex form and transformations, completed the square, and solved problems about thrown objects and areas. This unit builds those ideas into the language of functions. The companion unit Quadratic Expressions and Equations covers expanding, factoring, solving quadratic equations, the quadratic formula and the discriminant; this unit uses those tools. You will need a scientific calculator, graph paper, and if possible a free graphing tool such as Desmos.
Every lesson has worked examples with full solutions, diagrams, a hands-on activity, lots of practice with answers and a short quiz. The mathematical processes (problem solving, reasoning and proving, reflecting, selecting tools and strategies, connecting, representing and communicating) are woven through every lesson.
Curriculum expectations covered: The Ontario Curriculum, Grades 11 and 12: Mathematics (2007), Functions and Applications, Grade 11, University/College Preparation (MCF3M), strand A, Quadratic Functions: A2.1 to A2.11 (connecting graphs and equations of quadratic functions) and A3.1 to A3.3 (solving problems involving quadratic functions).