In most cases, only a single entry is needed.
However, in the top line, entries can be made in any, or all, of the boxes but there are some restrictions. If using this line, at least one of the entries must be greater than zero and, NO decimals or negatives are accepted. Negative values can be entered in the boxes below (if appropriate).
to_inf. means merely that the number is very large, tending to infinity. This can happen on the cosecant, secant, cotangent. In terms of this calculator, it will occur if a value in excess of 10 million is detected.
0 (or zero) is given if the value is less than 1 millionth