HP 39g+ - Page 167

Using mathematical functions 11-23
To find the
indefinite integral
using formal
variables
For example, to find the indefinite integral of
use:
1. Enter the function.
0
S1 3
X 5
X
2. Show the result format.
3. Press to close the
show window.
4. Copy the result and
evaluate.
Thus, substituting X for S1, it can be seen that:
This result is derived from substituting X=S1 and X=0 into
the original expression found in step 1. However,
substituting X=0 will not always evaluate to zero and may
result in an unwanted constant.
To see this, consider:
3x
2
5– xd
∫
()
∫
− XXS ,53,1,0
2
hp 39g+
3x
2
5– x 5x–3
x
3
3
-----
X∂
∂
X()
---------------





+=d
∫
x 2–()
4
x
x( 2 )
5
–
5
-------------------
=d
∫