CraigsMaths

Mathematics Teaching for Learning

Archive for the ‘Quadratic Equations’ Category

Factors of quadratics

Wednesday, August 13th, 2008

When factorising quadratics (or any trinomial) first identify the form of the expression and then apply the most direct method. If the expression is not in a recognisable form then manipulate it so that it is.

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Quadratic general to standard form

Wednesday, August 6th, 2008

When solving quadratic equations and sketching parabolas you can get the required points onto your graph very quickly if you know how to convert from the general form of y=ax^{2}+bx+c to the standard form of y=a\left(x-h\right)^{2}+k. (See Standard Quadratic Form for the reasons why.) This article explains how to complete the square to acheive this.

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Parabolas

Tuesday, August 5th, 2008

A parabola is a curve that is described by a quadratic equation. You may be presented with a quadratic equation in one of several forms and then asked to:

  • Sketch a graph of the equation
  • Find the local maxima or local minima
  • Find the vertex coordinates
  • Find the x-intercept(s) if they exist
  • Find the the y-intercept
  • Find the axis of symmetry

This article will describe the simplest approach for the different forms of the quadratic equation.

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General Quadratic Form

Tuesday, August 5th, 2008

The general quadratic form is:

y=ax^{2}+bx+c

This article will describe how to find the vertex, x-intercepts and y-intercepts for this form of a quadratic equation.

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Factored Quadratic Form

Tuesday, August 5th, 2008

If a quadratic can be factored it may be expressed in the following form:

y=a(x+h)(x+k)

This article will describe how to find the vertex, x-intercepts and y-intercepts for this form of a quadratic equation.

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