Saturday, March 14, 2009

Activity 1: Why is this an incorrectly drawn graph?

Draw the graph of y=x²+3x-5 for -4≤x≤2.

Activity 2: What is wrong with this table of values?

Draw the graph of y=x²-18x+110 for 1≤x≤14.


Activity 3: Properties of Quadratic Graphs

To further convince yourself of the property of quadratic graphs, you may select any 2 in each group to try sketching with Graphmatica.

Group A)
y=2x²+3x-5
y=2x²-8x+10
y=x²-16x+100

Group B)
y=-3x²-2x+12
y=-x²+2x-3
y=-3x²+4x+25

Activity 4: Test yourself

Give an equation that will produce a U-shaped curve.

[Take note that you are to use x^2 to represent x²]

Activity 5: Reinforce your learning at home

Try drawing these graphs using Graphmatica.

http://www.graphmatica.com

Group 1:
y=9x²
y=-x²
y=77x²

Group 2:
y=5x²
y=5x²-2
y=5x²+7

Activity 6: Category 3 graphs

Based on your observation for Category 3 graphs in your worksheet, at which values do you think these graphs will cut the x-axis?

a) y=x(x-4)
b) y=2x(x-3)


What has the equation of the graph y=x(x-4) got to do with the solving of the equation x(x-4)=0? How does this link to the values which the graph cuts at the x-axis?

Activity 7: Category 4 graphs

Based on your observation for Category 4 graphs in your worksheet, at which values do you think these graphs will cut the x-axis?

a) y=(x-3)(x+1)
b) y=(2x-1)(x-5)
c) y=(3x+2)(x-2)

Similary in Activity 6, what has the equation of the graph y=(x-3)(x+1) got to do with the solving of the equation (x-3)(x+1)=0? How does this link to the values at which the graph cuts the x-axis?