Incorrect result for exponational and logarithmic functions with exact results

[dovisutu]

Describe the bug
The below example shows a case that shown answer (2) doesn't match the real answer
log(e^2)/log(e)-2 != 0

Steps To Reproduce

Steps to reproduce the behavior:

1. Go to Scientific mode
2. enter log(e^2)/log(e^1)-2
3. See error

Expected behavior
log(e^2)/log(e^1)-2 should be 0 as base changing formula for logarithms:

Screenshots

Device and Application Information

• OS Build: 10.0.17134.0
• Architecture: X64
• Application Version: 10.1905.28.0
• Region: zh-CN
• Dev Version Installed: False

Additional context
This is a new issue related with #309 and #222
Requested Assignment
I'm just reporting this problem. I don't know how to fix it.

[SAI990323]

This is a matter of precision, I think you may not hope that the calculator will automate simplify the formula for you and if we use float number, this problem may be inevitable.

[dovisutu]

The issue is, if I delete "-2" part, the result is 2.
This may give somebody the thought,"How strange, why didn't 2-2 = 0?"
Also, there are two related issues mentioned, both of them are the case a-a != 0.

[MicrosoftIssueBot]

This is your friendly Microsoft Issue Bot. I've seen this issue come in and have gone to tell a human about it.

[grochocki]

Related to #222 and #309. Relevant article about this class of bugs in the calc engine.

[SAI990323]

The issue is, if I delete "-2" part, the result is 2.
This may give somebody the thought,"How strange, why didn't 2-2 = 0?"
Also, there are two related issues mentioned, both of them are the case a-a != 0.

sorry I misunderstand it.

[VIGNESHinZONE]

Can i work on this issue and could you pls tell me the files that i can work on.

[grochocki]

Thanks for taking a look! @joseartrivera, can you point @VIGNESHinZONE in the right direction here?