2 Equations, formulae and identities
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2.1 Use of symbols
understand that symbols may be used to represent numbers in equations or variables in expressions and formulae
Understand that algebraic expressions follow the generalised rules of arithmetic.
use index notation for positive and negative integer powers, including zero
use index laws in simple cases: xᵐ × xⁿ = xᵐ⁺ⁿ, xᵐ ÷ xⁿ = xᵐ⁻ⁿ and (xᵐ)ⁿ = xᵐⁿ
use index notation involving fractional, negative and zero powers
2.2 Algebraic manipulation
evaluate expressions by substituting numerical values for letters
collect like terms
multiply a single term over a bracket
take out common factors
expand the product of two simple linear expressions
understand the concept of a quadratic expression and factorise expressions limited to x² + bx + c
expand the product of two or more linear expressions
understand the concept of a quadratic expression and factorise quadratic expressions
manipulate algebraic fractions where the numerator and/or denominator can be numeric, linear or quadratic
complete the square for a given quadratic expression
use algebra to support and construct proofs
2.3 Expressions and formulae
understand that a letter may represent an unknown number or a variable
use correct notational conventions for algebraic expressions and formulae
substitute positive and negative integers, decimals and fractions for words and letters in expressions and formulae Evaluate 2x – 3y when x = 4 and y = −5
use formulae from mathematics and other real-life contexts expressed initially in words or diagrammatic form and convert to letters and symbols
derive a formula or expression
change the subject of a formula where the subject appears once
manipulate formulae or equations to change the subject, including cases where the subject appears twice or a power of the subject occurs
2.4 Linear equations
solve linear equations with integer or fractional coefficients in one unknown, where the unknown appears on either or both sides
set up simple linear equations from given data The three angles of a triangle are a°, (a + 10)°, (a + 20)°. Find the value of a
2.5 Proportion
set up direct or inverse proportion problems and relate algebraic solutions to graphs, using y ∝ x, y ∝ 1/x, y ∝ x², y ∝ 1/x², y ∝ x³, y ∝ 1/x³, y ∝ √x and y ∝ 1/√x
2.6 Simultaneous linear equations
2.6.AExact solutions of simultaneous linear equations
Calculate exact solutions of two simultaneous linear equations in two unknowns.
2.6.HAHigher-tier simultaneous linear equations
Calculate exact solutions of higher-tier simultaneous linear equations in two unknowns.
2.6.HBGraphical interpretation of simultaneous equations
interpret the equations as lines and the common solution as the point of intersection
2.7 Quadratic equations
solve quadratic equations by factorisation, limited to x² + bx + c = 0
solve quadratic equations by factorisation
solve quadratic equations by using the quadratic formula or completing the square
form and solve quadratic equations from data given in a context
solve simultaneous equations in two unknowns, one linear and one quadratic
2.8 Inequalities
understand and use the symbols >, <, ≥ and ≤, including double-ended inequalities
understand and use the convention for open and closed intervals on a number line
solve simple linear inequalities in one variable and represent the solution set on a number line
Represent simple linear inequalities on rectangular Cartesian graphs.
identify regions on rectangular Cartesian graphs defined by simple linear inequalities Conventions for the inclusion of boundaries are not required
solve quadratic inequalities in one unknown and represent the solution set on a number line
Identify harder regions on Cartesian graphs defined by linear inequalities.