8 Numeric Integration
Suppose we want to solve numerically a integral of the form
∫
a
b
f
x
dx
we write the function in the same way we did in the solver case.
Example: Calculate
∫
0
1
x
2
dx
.
First we enter the function as a program
01 LBL “FX”
02 MVAR “X” (also available in ∫f(x) menu)
03 RCL X
04 X↑2
05 RTN
06 END
Then we go to the ∫f(x) menu and what we have is
“Select ∫f(x) Program”
. In our case we select FX
then what appears is
“Set Vars; Select ∫var”
and we select X (before that we may set some
variables/constants if needed) and then we have to set
LLIM
(lower limit),
ULIM
(upper limit) and
ACC (Accuracy factor). In our case 0 LLIM and 1 ULIM and for ACC we can use 0.001. Now just
press ∫ and we find 0.33333028. If we set ACC to 0.000001 we will have 0.33333333333. In the
Free42 program the results may be little different.
