Algebraic skills
Expansion of brackets
Removing brackets is to multiply the term outside the brackets by each term inside - also known as the distributive law. Use FOIL to remove a pair of brackets then simplify by collecting like terms.
Factorising an algebraic expression
Factorising an expression is to write it as a product of its factors. There are 4 methods: common factor, difference of two squares, trinomial/quadratic expression and completing the square.
Completing the square in a quadratic expression
Completing the square is a method used to solve quadratic equations that will not factorise.
Simplifying algebraic fractions
Like other fractions, algebraic fractions can be simplified by cancelled down by dividing the numerator and the denominator by a common factor.
Applying the four operations to algebraic fractions
Algebraic fractions can be added, subtracted, multiplied or divided using the same basic rules as working with other fractions.
Determining the equation of a straight line
The equation of a straight line can be worked out using coordinates and the gradient, and vice versa.
Working with linear equations and inequations
As with other equations and inequations, when working with algebraic equations and inequations it is key to change operation when you change side.
Working with simultaneous equations
Simultaneous equations can be solved algebraically by first eliminating one of the unknowns so the other can be found.
Changing the subject of a formula
To change the subject of a formula the terms are rearranged following the general rule, change side, change operation.
Determine the equation of a quadratic function from its graph
The equation of a a quadratic function can be determined from a graph showing the turning point and another point on the graph.
Sketching a quadratic function
To sketch a quadratic function you must first determine the roots, nature and coordinates of the turning point and the y-intercept.
Identifying features of a quadratic function
The key features of a quadratic function are the y-intercept, the axis of symmetry, and the coordinates and nature of the turning point (or vertex).
Solving a quadratic equation
Revise the methods of solving a quadratic equation, including factorising and the quadratic formula. See a worked example of how to solve graphically.
Solving a quadratic equation using the quadratic formula
The quadratic formula can be used to solve any quadratic equation but is best saved for when an equation cannot be factorised.
Using the discriminant to determine the number of roots
Whether the discriminant is greater than zero, equal to zero or less than zero can be used to determine if a quadratic equation has no real roots, real and equal roots or real and unequal roots.
Video playlist
Solving simultaneous equations - using plums and peaches in China. Video
Using plums and peaches, Marcus du Sautoy shows how to solve simultaneous equations.
Bitesize maths: Factorising quadratic expressions. Video
An animated guide to factorising quadratic expressions and solving equations.
Bitesize maths: Simplifying equations. Video
An animated guide to simplifying algebraic expressions.
The Approximate History of Algebra. Video
A humorous, animated guide to the development of algebra.
Bitesize maths: Simultaneous equations. Video
An animated guide to solving simultaneous equations.
Islamic mathematics and the invention of algebra. Video
Marcus du Sautoy looks at the Arabic roots of the invention of algebra.
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