# Sage fails to evaluate this expression.

Sage doesn't seem to compute correctly `8*sin(pi/9)^3 - 6*sin(pi/9) + 3^(1/2)`

which is plain zero.

Sage fails to evaluate this expression.

**
asked 2015-03-29 11:12:06 +0200 **

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Sage doesn't seem to compute correctly `8*sin(pi/9)^3 - 6*sin(pi/9) + 3^(1/2)`

which is plain zero.

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2

Sage can compute it, but you must help it with reduce_trig():

```
a = 8*sin(pi/9)^3 - 6*sin(pi/9) + 3^(1/2)
a.reduce_trig()
0
```

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Asked: ** 2015-03-29 11:12:06 +0200 **

Seen: **141 times**

Last updated: **Mar 30 '15**

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