Quadratic Equation solution activity1

Objectives

Being able to identify the roots of the quadratic equations graphically.

Estimated Time

30 minutes

Prerequisites/Instructions, prior preparations, if any

Knowledge about equations, linear equations, meaning of quadratic equations

Materials/ Resources needed

• Click here to open the file

• This Geogebra file can be used to show Graph and zeroes of Quadratic polynomials.

Process (How to do the activity)

Download this geogebra file from this link.

Procedure:

The general form of quadratic equation is ax²+bx+c=0,where a, b, c are known values, x is variable and a≠0.This equations can also occur in different forms such as ax²+bx=0, ax²+c=0 and ax²=0.

1. Open the Geogebra file
   1. Start with values of b=0, c=0
   2. Change value of a to 1 (keeping b=0, c=0 and see what happens)
   3. Change value of c to 1, 2, 3 etc (keeping a=1, b=0 and see what happens)
   4. Change value of b to 1, 2, 3 etc (keeping a=1, c=0 and see what happens)
2. In each of the above cases, discuss with students the meaning of the curve plotted and how the curve changes on change in values.
3. Identify and note down the roots of the given set of values for a, b, c in quadratic equations.

Evaluation at the end of the activity

In quadratic equations why is a≠0? What happens to the quadratic equation, if a=0?

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