# Conjugate multiplication of square root

Is there a simple way to simplify a formula using conjugate multiplication of the square roots? For example, when I perform

```
var('a,b,d')
exp = 1/(a+b*sqrt(d))
exp.full_simplify()
```

I would like to get

```
(b*sqrt(d) - a)/(b^2*d - a^2)
```

but what I actually get is just the form that I started with. Even if I specify the assumptions

```
assume(d,'real')
assume(d>0)
```

the conjugate multiplication does not happen automatically. I would like to be able to tell Sage, that I want the conjugate multiplication. In some cases that are relevant to me, the conjugate multiplication would simplify my expressions significantly.