Sharp EL-5230 - Manual (Page 40)

38
Differential/Integral Functions
Differential and integral calculations can only be performed in the NORMAL
mode. It is possible to reuse the same equation over and over again and to
recalculate by only changing the values without having to re-enter the
equation.
• Performing a calculation will clear the value in the X memory.
• You can use both global and local variables in the equation.
• The answer calculated will be stored in the last answer memory.
• The answer calculated may include a margin of error, or an error may
occur. In such a case, recalculate after changing the minute interval (dx)
or subinterval (n).
• Since differential and integral calculations are performed based on the
following equations, in certain rare cases correct results may not be
obtained, such as when performing special calculations that contain
discontinuous points.
Integral calculation (Simpson’s rule):
S=—h{f (a)+4{f (a+h)+f (a+3h)+······+f (a+(N–1)h)}
+2{f (a+2h)+f (a+4h)+······+f (a+(N–2)h)}+f(b)}
N=2n
h =
b – a
N
a ≤x≤b
1
3 ——
Differential calculation:
f (x+ ––)–f (x– ––)
dx
2
dx
2
f’(x)=————————
dx
Differential function
The differential function is used as follows.
1. Press b 0 to enter the NORMAL mode.
2. Input a formula with an x variable.
3. Press @ 3.
4. Input the x value and press e.
5. Input the minute interval (dx).
6. Press e to calculate.
Chapter 3: Scientific Calculations