Infinity constants on WP-34s

[Marcel Samek]

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?

[Paul Dale]

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

[Marcel Samek]

Out of curiosity, are there any functions on the WP-34s where the infinity constants can actually be used?

[Paul Dale]

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

[Paul Dale]

Also stuff like 1/infinity = zero and 1/-infinity = - zero.

- Pauli