## #2588 Maxima ignores input to asksign

None
open
nobody
5
2014-07-22
2013-06-05
Barton Willis
No

OK:

```(%i1) integrate(x^mu * atan(x),x);
"Is  "mu+1"  zero or nonzero?"zero;

(%o1) -(%pi*log(x^2+1)+2*%i*li[2](%i*x+1)-2*%i*li[2](1-%i*x)-4*atan(x)*log(x))/4
```

Not OK--the antiderivative isn't valid when mu + 1 = 0

```(%i2) integrate(x^mu * acos(x),x);
"Is  "mu+1"  zero or nonzero?"zero;
(%o2) -((mu+1)*integrate((sqrt(1-x)*x*sqrt(x+1)*%e^(mu*log(x)))/((mu+1)*x^2-mu-1),x)-x*%e^(mu*log(x))*atan2(sqrt(1-x)*sqrt(x+1),x))/(mu+1)
```

## Discussion

• Robert Dodier
2013-07-22

• labels: --> Lisp Core - Integration, Lisp Core - Assume
• Description has changed:

Diff:

```--- old
+++ new
@@ -1,14 +1,17 @@
OK:

+~~~~
(%i1) integrate(x^mu * atan(x),x);
"Is  "mu+1"  zero or nonzero?"zero;

(%o1) -(%pi*log(x^2+1)+2*%i*li[2](%i*x+1)-2*%i*li[2](1-%i*x)-4*atan(x)*log(x))/4
+~~~~

Not OK--the antiderivative isn't valid when mu + 1 = 0

+~~~~
(%i2) integrate(x^mu * acos(x),x);
"Is  "mu+1"  zero or nonzero?"zero;
(%o2) -((mu+1)*integrate((sqrt(1-x)*x*sqrt(x+1)*%e^(mu*log(x)))/((mu+1)*x^2-mu-1),x)-x*%e^(mu*log(x))*atan2(sqrt(1-x)*sqrt(x+1),x))/(mu+1)
+~~~~

-
```

• Robert Dodier
2013-07-22

I put leading and trailing tildes (~~~~) around Maxima i/o, and assigned labels.