HP 35s User Manual page 340

Try it and see what happens. Enter the function f(x) = xe
Keys:

X 
 X
 

Set the display format to SCI 3, specify the lower and upper limits of integration as
499
zero and 10 , than start the integration.
Keys:
8
(2)



X
The answer returned by the calculator is clearly incorrect, since the actual integral of
–x
f(x) = xe from zero to
represented by 10
very close to 1. The reason for the incorrect answer becomes apparent from the
graph of f(x) over the interval of integration.
E-4
More about Integration




 _



∫ 

is exactly 1. But the problem is not that
499
, since the actual integral of this function from zero to 10
Display:
Display:


–x
.
Description:
Select equation mode.
Enter the equation.
End of the equation.
Checksum and length.
Cancels Equation mode.
Description:
Specifies accuracy level
and limits of integration.
Selects Equation mode;
displays the equation.
Approximation of the
integral.
was
499
is