Last week we looked at factorising Quadratics; this week we start building on factorising by:
In part 1 - looking at what would factorise
In part 2 - I would like to remind you how to complete the square and assemble a proof for the "Quadratic Formula".
In part 3 - you will think about the different representations of Quadratics and what they tell you about the graphs.
Have a look through the questions below. They do increase in difficulty. Below the questions you should find a link to the solutions.
Please watch the video below for a quick refresher of how to Complete the Square. Attempt the questions and then try to prove the Quadratic Formula.
x^2-4x-5
8x^2-9x+7
3-6x-x^2
How can completing the square help with finding the vertex/line of symmetry in a quadratic graph?
Now complete the square to solve the general quadratic ax^2+bx+c=0
The result should look familiar.
You can use the card sort below to help you!
Can you solve this problem about maximising an enclosure size?
We need to solve maximisation and minimisation problems all the time - from maximising profits to making airplanes fly.
What can you tell about the graph from the equation and vice-versa . You may find this graphing website useful:
Why care about quadratic graphs at all? Well, if you want your maths to be in some way useful then have a look at this article explaining about parabolic mirrors - this is all based on results you can prove with A-Level Maths.