Explain the use of the quadratic formula to solve quadratic equations.
To explain this to a student, I would start by explaining the general formula for a quadratic equation, (ax^2 + bx + c = 0). Then I would show using an example, how the a,b and c can be substituted with numbers. I would then check that they could arrange an equation into this layout if they were given one in the form of ax^2 + bx = -c for example.
Next I would state the quadratic formula, that will be given on formula sheets for gcse. I would then explain with an example, how a quadratic equation can be substituted into this, and then explain step by step how to solve it.
Next I would give the student an example question and ask them to try to solve it themselves as I gave guidance to check that they understood.
If relevant to the syllabus being studied, I would then explain why this is useful e.g. to find the x intercept of a graph. I would also give some scenarios where you can choose which of the two answers is the right one, such as when answers below zero are invalid.
Related Maths GCSE answers
All answers ▸There are 5 red balls and 7 green balls in a bag. A ball is taken from the bag at random and not replaced. Then a second ball is taken from the bag. What is the probability that the 2 balls are the same colour?
When will I ever need to use this in real life?
There are 20 sweets in a bag, 5 are white and 15 are black. What is the probability that a sweet chosen at random will be white?
Write 2x^(2) + 9x + 1 in the from a(x+m)^(2) + n, and hence solve 2x^(2) + 9x + 1= 0, leaving your answer in surd form.