12/Integrals - Casio FX-180PA Manual

12/INTEGRALS
To carry out integrals, C define (write) function j(x) during the LRN mode, then® desig-
nate the interval of integral during the Jdx mode.
j(a)
j(h) r = .r(.r)
b
We calculate area rj(x)dx.
a h
N equal parts
The approximation method used for integrating the function written in P1 or P2 is the
Simpson's rule. This method requires to divide the interval of integral into equal parts.
If the number of divisions is not specified, the calculator determines it by itself according
to the form of the function. To specify it, designate n (an integer of 1 to 9) which meets
N=2" where N is the number of divisions.
■ Defining funciton f(x)
1) Select the LRN mode (press
l! l
).
2) Designate a program number (press ai( or Pz ).
3) Press
This is needed, as the first program step, to assign variable x of the function j(x) to
the M-register.
4) Write the expression of function f(x) by true algebraic logic. Use Ma to represent vari-
able x. Write Ø at the end.
Ex.) For j(x)= xZ1 1 , write the sequence of 1, =, [(, MR, SHIFT x 2, +, 1, )), _.
5) Press Øe Q to select the Jdx mode.
Note: For a function j(x) whose variable x cannot take the zero value, input an appropri-
ate number in between steps 1) and 2) above.
Do not use constant registers, I
, ® and xu during expressing a function (step 4).
■ Execution of integral
1) Select the jdx mode (press ®~).
2) Designate the program number assigned to the function, f(x), (Press ri or Pz.)
3) Press a sequence of n ® ® to specify division number N (this will be displayed). This
step may be skipped.
4) Designate the interval of integral, [a, b]. (Press a wx b aN.(
In seconds or minutes the result will be displayed in a floating point representation.
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