# What is the opposite of log_expand

log_expand does converts log(x*y) to log(x)+log(y). Is there a function which explicitly reverts this?

What is the opposite of log_expand

add a comment

2

Yes, `log_simplify`

:

```
sage: e = log(x*y) ; e
log(x*y)
sage: f = e.log_expand() ; f
log(x) + log(y)
sage: f.log_simplify()
log(x*y)
```

Note that given an sage object `e`

, you can see all methods that can be applied to it, by typing `e.<TAB_BUTTON>`

, and the methods that start with `blah`

by typing `e.blah<TAB_BUTTON>`

, in particular, you could discover both methods by typing:

```
sage: e.log<TAB_BUTTON>
```

Please start posting anonymously - your entry will be published after you log in or create a new account.

Asked: ** 2018-01-28 13:13:58 +0200 **

Seen: **166 times**

Last updated: **Jan 28 '18**

why won't simplify multiply out square roots?

Symbolic expressions and simplifying

No simplification is done to invert trigonometric functions ?

Factorial simplification error

Dropping higher powers of a variable in an expression

simplification errors in simple expressions

Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.