Opened 10 years ago

# Maxima missing rectform simplification after integral()

Reported by: Owned by: jan burcin major sage-6.4 symbolics kcrisman N/A

### Description

```var('a b c x', domain='real')
A = (sin(a) * x^2+sin(b) *x + sin(c)) * exp(-x^2)
Aint = A.integrate(x,-infinity,infinity)
```

A.imag() is 0

Aint.imag() is a long expression, which doesn't simplify to 0. This surprising for the user.

A slightly different example, actually a generalization of the one above, just works:

```var('a b c x', domain='real')
B = (a * x^2+b *x + c) * exp(-x^2)
Bint = B.integrate(x,-infinity,infinity)
```

Examples can be found here: http://demo.sagenb.org/home/pub/179

### comment:2 Changed 8 years ago by jdemeyer

• Milestone changed from sage-5.11 to sage-5.12

### comment:3 Changed 7 years ago by vbraun_spam

• Milestone changed from sage-6.1 to sage-6.2

### comment:4 Changed 7 years ago by vbraun_spam

• Milestone changed from sage-6.2 to sage-6.3

### comment:5 Changed 7 years ago by vbraun_spam

• Milestone changed from sage-6.3 to sage-6.4

### comment:6 Changed 6 years ago by rws

• Summary changed from A.integrate() has imaginary part for real A to Maxima missing rectform simplification after integral()

This seems to be a missing rectform simplification because

```sage: Aint.expand().simplify_rectform()
1/2*sqrt(pi)*sin(a) + sqrt(pi)*sin(c)
```

The bug is then rather that Maxima does it not in all cases.

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