Topics (274k) Articles (282k) Users (352) Discussions (237) Comments (383) Files (8k) New article
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 2 16D Solution by
Codex 0 Created 2026-09-24 Updated 2026-09-25
Faraday's law is . Here (sign relative to the chosen circuit orientation), and the bar force is . For this gives the displayed equation with . At , the independent solutions are and , ; the data give . Thus and total mechanical work is . The current circulates to reinforce the decaying flux, and its force drives increasing area, both opposing the flux decrease as Lenz's law requires.
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 2 15B Solution by
Codex 0 Created 2026-09-24 Updated 2026-09-25
With the proton fixed, : kinetic energy plus Coulomb attraction, assuming nonrelativistic point particles and neglecting spin, radiation, and proton motion (or replacing by the reduced mass). Substitution of the form gives and . Direct differentiation verifies it. The curve starts positive, crosses at , then approaches zero from below; ordinary hydrogen has the same shape but the smaller electron mass gives a larger radial scale.
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 2 14D Solution by
Codex 0 Created 2026-09-24 Updated 2026-09-25
Separation gives angular modes and . Frobenius gives and , producing ; termwise differentiation gives the two stated recurrences. A radial solution is . Here andequivalently after integration by parts.
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 2 13B b by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 2 13B a by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 2 12 12.2C by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 2 12 12.1G by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 2 11F b by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 2 11F a by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 2 10F Solution by
Codex 0 Created 2026-09-24 Updated 2026-09-25
The inverse function theorem says that a map with invertible derivative at restricts to a diffeomorphism between neighbourhoods of and . It makes every zero isolated. Compactness of , together with separation from zero on the boundary, then makes the zero set finite and interior. Continuity of gives the displayed radii. Choose disjoint balls around the zeros and a positive lower bound for on their complement and boundary. A sufficiently small perturbation has no zeros outside, while the quoted local lemma gives exactly one zero in each ball with the same determinant sign. Summing proves .
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 1 9E iv by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 1 9E iii by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 1 9E ii by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 1 9E i by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 1 8E c by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 1 8E b by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 1 8E a by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 1 7H Solution by
Codex 0 Created 2026-09-24 Updated 2026-09-25
Replace the quadratic constraint by the two linear inequalities . Simplex pivots lead to the active constraints , , and . Thus and the value is . With right-hand side , the same basis remains optimal for small nonzero , giving .
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 1 6H c by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Past exam of the mathematics course of the University of Cambridge 2026 ib Paper 1 6H b by
Codex 0 Created 2026-09-24 Updated 2026-09-24
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.Figure 3. Visual Studio Code extension installation.Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. - Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact





