3.

The two chairs that I used in my experiment for question number 1 & 2 were at the same height. The height of two chairs is 90 centimetre. The distance between two chairs is 210 centimetres long. The support on the left-handside (y-axis) | The floor(x-axis) | 90.0 | 0 | 65.5 | 15 | 45.0 | 30 | 30.1 | 45 | 18.8 | 60 | 10.6 | 75 | 6.0 | 90 | 4.6 | 105 | 6.1 | 120 | 10.7 | 135 | 19.0 | 150 | 30.1 | 165 | 45.0 | 180 | 65.1 | 195 | 90.0 | 210 |

4.

5. The equation of turning point form of a parabola is y=a(x-h)2+k , substitute the turning point (105, 4.6), and sub the y-insert (0, 90.0) into the turning point equation.

Solution: y=a(x-h)2+k 90.0=a(0-105)2+4.6 85.4=11025a a=0.0077460317

So the turning point equation is y=0.0077460317x-1052+4.6 .

6.

This graph is from Microsoft Excel.

7.

Put the data from the experiment into computer and use the CAS calculator and computer to calculate the equation and all the results are checked twice, so they are accuracy. The results are reliable. * The turning point model isn’t accurate. * The quadratic model could make calculation mistakes.

Strengths: * The turning point model is convenient, because this model only need to use mainly the turning point and another point from the curve for the original turning point form equation (y=(x-a)2+b), and then get the equation for the experiment data. * The quadratic model is accurate, because finding