MEI Tasks for Casio Graphical Calculators
Using the Casio fx-9750G Plus
1. Drawing lines of the form x
 c :
From the main menu: select option 5 (GRAPH): then F3 (TYPE): followed by F4 (X=C):
Now enter 2: then EXE followed by F6 (DRAW): showing the graph of x

2
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MEI Tasks for Casio Graphical Calculators
2. Drawing inequalities such as y
 x
2 
1 :
From the main menu: select option 5 (GRAPH): then F3 (TYPE): followed by F6 (more options): and F1 (Y>): x
2 
1 and EXE: followed by F6 (DRAW): showing the region satisfying y
 x
2 
1 .
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MEI Tasks for Casio Graphical Calculators
3. Summing an AP given the general term and the number of terms.
From the main menu: select option 1 (RUN) followed by the OPTN key: then F4 (CALC) and F6(more options) and then F3 (  ):
To sum the AP (with 8 terms) k
8 

1
3 k

1
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MEI Tasks for Casio Graphical Calculators
4. Evaluating d
2 y d x 2
at a point on curve.
From the main menu: select option 1 (RUN) followed by the OPTN key: then F4 (CALC) and F3 ( d
2 y d x
2
):
Now to evaluate d
2 y d x
2
at the point x

2 on the curve y
 x
3 
2 x
2 :
Similarly to find
1
 3
2 d , choose F4 (
 d x ):
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MEI Tasks for Casio Graphical Calculators
5. Plotting a family of curves dynamically.
To plot y

Ax
2 for A

1, 2,3, 4 :
From the main menu: select option 6 (DYNA): and (using the ALPHA button to access the variable A) enter y

Ax
2 followed by EXE:
To set the range for A press F4 (VAR) then 1 (for the initial value of A ): followed by F2 (RANGE) and set End to 4 and Pitch to 1:
EXIT followed by F6 ( DYNA) and after “One moment please” the graphs will be drawn in sequence a total of 10 times.
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MEI Tasks for Casio Graphical Calculators
6. Given the y co-ordinate of a point on a graph determining the corresponding x co-ordinate
From the main menu: select option 5 (GRAPH): then y


2 
4

and EXE: and F6 (DRAW):
SHIFT F5 (G-SLV) followed by F6 (more options) and F2 (XCAL) prompts you for the y coordinate you are interested in:
Try y

1.5
and EXE:
Press the right cursor ► to get the next point with y coordinate 1.5: and ► again:
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MEI Tasks for Casio Graphical Calculators
7. Drawing a line that is the tangent or the normal to a point on a graph.
From the main menu: select option 5 (GRAPH): then, say, y
 x
3 
4 x

4 : and F6 (DRAW):
To draw a tangent to the curve at a chosen point select the Sketch menu
(SHIFT and F4) followed by F2 (Tang) and then you are prompted to move the cursor to your chosen point: and EXE draws the tangent:
F3 rather than F2 would draw the normal. Due to the scales on the graph, the tangent and normal do not look perpendicular – a good discussion point:
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MEI Tasks for Casio Graphical Calculators
8. Using the dual graph to view the graph of a function alongside an enlarged region.
From the main menu: select option 5 (GRAPH): then enter, say, y
 x
2 and y x 3 : followed by F6 (DRAW):
SHIFT and SET UP and ▼▼ followed by F1 (Grph): then EXIT and F6 (DRAW):
SHIFT F2 (Zoom), F1 (Box) and using the cursors and EXE to select a region to enlarge:
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MEI Tasks for Casio Graphical Calculators
9. Drawing a dynamic graph using the built-in functions.
From the main menu: select option 6 (DYNA): and then F5 (B-IN): followed by ▼ and F1 (Select):
You will need to give values to two of these and choose a range of values for the third. First using the cursor ▼ and EXE choose values for A, B and C:
Now highlight B=-2 (you might need to use EXE) and press F1 (Select) and this will be the dynamic coefficient:
F2 (Range) allows you to select the range of values for B:
F3 (Speed) allows you to change the speed at which the graphs are plotted and F6 (DYNA) shows the family of curves plotted in sequence:
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MEI Tasks for Casio Graphical Calculators
10. Graphing circles
From the main menu: select option 9 (Conics): and ▼to circles:
EXE then allows you to choose values for the coordinates of the centre (H,K) and the radius:
F6 (DRAW): looks like an ellipse so a combination of
SHIFT F2 (Zoom), F6, F2 (SQR) and SHIFT F3 (V-Window) results in a circular circle!
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MEI Tasks for Casio Graphical Calculators
11. Solving equations
From the main menu: select option 1 (RUN) and then OPTN F4 (CALC):
Press F1 (Solve) and then input the expression. For example, if you want to solve the equation x
3 
4 x

1 finding the root near 2:
You can also find the root near 0 by pressing the
◄ key and editing: and similarly the root near
–2:
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MEI Tasks for Casio Graphical Calculators
12. Recursive functions
From the main menu: select option 8 (RECUR): and then F3 ( a n

2
):
Example 1. The Fibonacci sequence.
Press key F4: then enter a n

2
 a n

1
 a n
You could use F1 to generate
A.P.s such as a n

3 n

1
then F5(Range) and EXE
using F3 and F2 and EXE: the following values
EXE twice at the end takes F6(Table) gives the Fibonacci sequence, you back to the previous screen: using the ▼ key to see further values.
Example 2. Adding the terms of a GP
Following the instructions above… and this generates the GP
1
,
2
,
3
,...
with first term 2 and common ratio 1.5 and the sum of this GP: b n
 r n 

1 a r
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MEI Tasks for Casio Graphical Calculators
13. Dealing with derivative functions.
From the main menu: select option 5 (GRAPH) along with the graph shown:
OPTN F2 (CALC) VARS, F4(GRAPH) and F1 (Y) followed by 1,X) EXE: followed by F1(d/dx):
SHIFT F3 (V-Window) and these settings: and EXE takes you back to the previous screen :
Finally F6 (DRAW): showing the graph of y
  
2
 x

2
  x
3 
4 x and the derivative function
Y 2
 
3 x
2 
4 . d x
Lots of interesting questions can be asked here:

What is special about the three points where the graph of Y2 crosses the axes?

What happens to the two graphs as x
 
?

Is y
 x
3 
4 x an odd function? Does this mean that d y d x even function? must be an

Is there anything special about the points where the two graphs intersect? In how many places do they intersect?
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