# Changes between Initial Version and Version 5 of Ticket #3732

Ignore:
Timestamp:
10/02/09 16:37:46 (12 years ago)
Comment:

Here is the current state of this ticket. Of the examples in the first attached file, the following are legitimate bugs of this type.

The first example has unnecessary questions.

```sage: integrate(1/sqrt(x-q), x, 1, 2)
2 sqrt(2 - q) - 2 sqrt(1 - q) # should be this always
```

The third example is definitely a case for this, as of Maxima 5.19.1:

```(%i19) integrate(log(q-x), x, a, b);
Is  b - a  positive, negative, or zero?

positive;
(%o19)          (b - q) log(q - b) - (a - q) log(q - a) - b + a
(%i20) integrate(log(q-x), x, a, b);
Is  b - a  positive, negative, or zero?

negative;
(%o20)          (b - q) log(q - b) - (a - q) log(q - a) - b + a
(%i21) integrate(log(q-x), x, a, b);
Is  b - a  positive, negative, or zero?

zero;
(%o21)          (b - q) log(q - b) - (a - q) log(q - a) - b + a
```

The fifth example has MANY questions to ask, always the same answer:

```(%i36) integrate(1/sqrt(q^2-x^2),x, a, b);
Is  b - a  positive, negative, or zero?

negative;
Is  q - a  positive, negative, or zero?

zero;
Is  q + a  positive, negative, or zero?

zero;
Is  q + b  positive, negative, or zero?

positive;
b              a
(%o36)                    asin(------) - asin(------)
abs(q)         abs(q)

```

++++++++++++++++++++++++++++++++

The following should not be considered bugs, at least not for the reason given.

The second example is okay:

```sage: integrate(1/(x-q),x,1,2)
```

Maxima adds pi*I and/or switches q-2 to 2-q as appropriate. If we don't like those differences, that should be on a different ticket.

The fourth example is:

```sage: integrate(1/(q-x^2), x)
```

The answers given are a constant away from each other, but look very different. This probably should be considered a bug (Maxima can't connect between logs and arctan/h stuff), but is likely to not be resolved soon, or by questions.

The last example is definitely not a bug, as for q=-1 you should get a different answer!

### Legend:

Unmodified
• Property Summary changed from `calculus -- some examples of sage integration failing` to `Unnecessary Maxima interactions in integration`