## Before You Watch

This video demonstrates how to solve a particular type of equation called a quadratic equation.
To get the most out of this topic, you'll need to be comfortable with the rearrangement of algebraic equations, as well as indices as they are applied to algebra. If you need to brush up on your skills in these areas, take a look at the Introduction to Algebra and Indices Laws videos first, then come back.

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## Now What?

You may find it helpful to follow through and see how the quadratic formula is created. You can see the derivation in the Maths Is Fun website at http://www.mathsisfun.com/algebra/quadratic-equation-derivation.html. ]. It is not necessary to know this derivation, but it might assist your understanding. Another option for watching the derivation of the quadratic formula is the video by PatrickJMT at http://patrickjmt.com/deriving-the-quadratic-formula/ .

Now that you're familiar with the use of the quadratic equation, why not check your skills in some of the areas covered by the other algebra videos? Factorisation of Algebraic Expressions  is particularly relevant to the alternative method of solving quadratic equations. Others such as Algebraic Fractions and Simultaneous Equations will also help develop your abilities in algebra.

## But When I am Going to Use This

Quadratic equations are very important as they are useful in understanding situations such as movement under constant acceleration (like gravity), a thrown ball if we ignore wind resistance, or pendulums or weights on springs. In fact, the quadratic equation is the base level solution for all stable systems, so it's one of the most widely studied systems in physics and engineering. Some stable systems that are often approximated using a quadratic equation include an atom’s position in a molecule or solid, a thermostat attempting to maintain a constant temperature, or even a child on a swing.