Scheme of work: GCSE Higher: Year 11: Term 1: Quadratic Equations

#### Prerequisite Knowledge

• Simplify and manipulate algebraic expressions by:
• Expanding products of two or more binomials
• Factorising quadratic expressions of the form x2 + bx + c, including the difference of two squares
• Simplifying expressions involving sums, products and powers, including the laws of indices
• Factorising quadratic expressions of the form ax2 + bx + c.

#### Success Criteria

• Know the difference between an equation and an identity; argue mathematically to show algebraic expressions are equivalent and use algebra to support and construct arguments and proofs.
• Simplify and manipulate algebraic expressions by factorising quadratic expressions of the form ax2 + bx + c.
• Understand and use standard mathematical formulae; rearrange formulae to change the subject
• Identify and interpret roots, intercepts, turning points of quadratic functions graphically
• Deduce roots algebraically and turning points by completing the square
• Recognise, sketch and interpret graphs of quadratic functions
• Solve quadratic equations (including those that require rearrangement) algebraically by factorising, by completing the square and by using the quadratic formula; find approximate solutions using a graph
• Solve two simultaneous equations in two variables linear/quadratic algebraically; find approximate solutions using a graph

#### Key Concepts

• Check brackets have been factorised correctly by multiplying them back out.
• To solve quadratics by factorising, students must identify two numbers with a product of c and a sum of b.
• When a quadratic cannot be solved by factorising students should use completing the square or the quadratic formula.
• Students should be able to derive the quadratic formula from the method of completing the square.
• A sketched graph is drawn freehand, including the roots, turning point and intercept values.
• Quadratic and linear simultaneous equations should be sketched before solved algebraically to ensure students know to find and the x and y values.

#### Common Misconceptions

• The trial and improvement method is often incorrectly used to try and solve quadratics.
• When solving quadratic and linear simultaneous equations students often forget to find the y values as well the x.
• When using the formula to solve quadratics students often forget to evaluate the negative solution. Some students also incorrectly apply the division by reducing the terms it covers.
• Students tend to struggle deriving quadratic equations from geometrical facts.

## Quadratic Equations Resources

### Mr Mathematics Blog

#### Planes of Symmetry in 3D Shapes

Planes of Symmetry in 3D Shapes for Key Stage 3/GCSE students.

Use isometric paper for hands-on learning and enhanced understanding.

#### GCSE Trigonometry Skills & SOH CAH TOA Techniques

Master GCSE Math: Get key SOH-CAH-TOA tips, solve triangles accurately, and tackle area tasks. Ideal for students targeting grades 4-5.

#### Regions in the Complex Plane

Explore Regions in the Complex Plane with A-Level Further Maths: inequalities, Argand diagrams, and geometric interpretations.