The manual (3.1) says that the constants positive and negative infinity are considered numeric values.
However, if I try using them as limits to the integrate operator, I get a "not numeric" error.
Is this a bug or by design?
By design.
The integration code cannot handle infinite limits, so they are disallowed. There are transforms that can be used to reduce the limits to something finite -- old HP manuals detail one procedure.
- Pauli
Out of curiosity, are there any functions on the WP-34s where the infinity constants can actually be used?
Yes, plenty. Two easy ones: e-infinity gives zero and TANH(infinity) is one.
If you are going to start playing with infinities on the 34S, make sure you set the D flag.
- Pauli
Also stuff like 1/infinity = zero and 1/-infinity = - zero.
- Pauli