MEI Tasks for Casio Graphical Calculators
Introduction to Stationary Points on the fx-9860
Maxima and minima on quadratic functions
1. Open the Graphs screen:
pY
2. Enter a quadratic function as Y1
e.g. Y1=X²–6X+3
3. Enter its derivative as Y2
e.g. Y2=2X–6
4. Toggle the Graph view:
u
Questions
Can you explain the relationship between the graph of the quadratic function and its derivative?
What is happening on the graph of the derivative when the quadratic function is at a minimum?
Can you give an example of a quadratic function that has a maximum?
Can you explain the difference between the equation of the tangent to a curve at a point and the
equation of the gradient.
Maxima and minima on cubic functions
1. Open a new Graphs screen:
p Y
2. Enter a cubic function as Y1 where the
coefficient of x³ is positive and the
coefficient of x is negative
e.g. Y1=X³+3X²–2X+1
3. Toggle the Graph view:
u
4. Use G-Solv to find the maximum and minimum:
yw and ye
Questions
Can you confirm the coordinates of the maximum and minimum point using the derivative?
Can you find an example of a cubic function that has 0 stationary points? Can you find an example
of cubic function that has 1 stationary point?
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v1.0 28/08/13