josdejong/mathjs

Nested derivatives fail

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#3,528 opened on Sep 8, 2025

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bughelp wanted

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Description

Describe the bug mathJs evaluates this derivative correctly: derivative('x * e^x', "x") // returns "e ^ x * (x + 1)"

however, if the expression to be differentiated is involves another derivative mathJs returns an incorrect answer: derivative('x * derivative("e^x", "x")', "x") // returns "e^x"

To Reproduce enter expression in mathJs demo window: derivative('x * derivative("e^x", "x")', "x")

Contributor guide

Research direction
Examine how the derivative function handles nested calls and trace the symbolic computation path.
Tech stack
javascript
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaScriptcalculus
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50