# Simple exponential expand

**URL:** <https://community.wolfram.com/t/simple-exponential-expand/25227>\
**Category:** Questions\
**Tags:** algebra\
**Created:** [March 9, 2025, 10:55pm UTC](https://community.wolfram.com/t/simple-exponential-expand/25227 "2025-03-09T22:55:27Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![hlyr314](https://avatars.discourse-cdn.com/v4/letter/h/e47c2d/32.png) [@hlyr314](https://community.wolfram.com/u/hlyr314)\
**Post date:** [March 9, 2025, 10:55pm UTC](https://community.wolfram.com/t/simple-exponential-expand/25227/1 "2025-03-09T22:55:27Z")

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Is there a way to expand an exponential of a sum to a product of exponentials? Example:

```
Exp[a+b]

```

I want Mathematica to expand it to `Exp[a]*Exp[b]`. In my example, the full expression is `Exp[a+b]+c*Exp[a+d]` and I want to factor with respect to `Exp[a]` and expand to trig the terms `Exp[b]` and `Exp[d]`, where b and d are imaginary numbers.

Thanks!

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<div class="post-metadata">

**Author:** ![mroge02](https://yyz1.discourse-cdn.com/wolfram/user_avatar/community.wolfram.com/mroge02/32/28775_2.png) [@mroge02](https://community.wolfram.com/u/mroge02)\
**Post date:** [March 10, 2025, 1:24am UTC](https://community.wolfram.com/t/simple-exponential-expand/25227/2 "2025-03-10T01:24:04Z")

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Since `Exp[a] Exp[b]` automatically evaluates to  
`Power[E, Plus[a, b]]`,  
it’s impossible to keep `Exp[a] Exp[b]` as is, unless you use `Hold[]` or `HoldForm[]`.

On the other hand, we have this:

```
Factor[Exp[a + b] + c Exp[a + d]]
(* E^a (E^b + c E^d) *)

```

If a, b, c, d have numeric values, then you have to take a more manual approach, since the numbers will combine with one another. Try the following:

```
Exp[a] Expand[(Exp[a + b] + c Exp[a + d])/Exp[a]]

```

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<div class="post-metadata">

**Author:** ![gianlucagorni](https://avatars.discourse-cdn.com/v4/letter/g/ec9cab/32.png) [@gianlucagorni](https://community.wolfram.com/u/gianlucagorni)\
**Post date:** [March 11, 2025, 9:41am UTC](https://community.wolfram.com/t/simple-exponential-expand/25227/3 "2025-03-11T09:41:54Z")

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Just one variation:

```
Exp[a + b] + c Exp[a + d] /. a -> Log[Defer[E^a]]

```
