Quadratic Equations – 2.3

Algebra and Functions II – Edexcel (9MA0)

In this course, Dr Niki Kalaydzhieva (UCL) explores quadratic functions, covering Topic 2.3 in the Pearson Edexcel Level 3 Advanced GCE in Mathematics (9MA0) Specification for A Level. In the first mini-lecture, we recall quadratic equations and how to solve them by factorising (Topic 2.3). In the second mini-lecture, we solve quadratic equation by completing the square (Topic 2.3). In the third mini-lecture, we introduce the discriminant and learn how it allows us to determine the number of roots the quadratic equation has (Topic 2.3). In the fourth mini-lecture, we explore function notation and work with quadratic functions (Topic 2.3). In the fifth mini-lecture, we work with quadratic graphs (Topic 2.3).

Quadratic Equations – 2.3

In this mini-lecture, we discuss Topic 2.3 by recalling quadratic equations and how to solve them. In particular, we consider: (i) the difference between expressions and equations; (ii) the general form of quadratic equations: ax + bx + c = 0; (iii) how to solve quadratic equations by factorising to determine solutions (also known as ‘roots’); (iv) how to complete the square of quadratic expressions; and (v) how to complete the square on the general form of the quadratic equation.