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Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 2 11 c Solution by
Codex 0 2026-10-18
Use the usual model of independent games, each with Sheila-win probability . After games, an outcome with wins and losses has possible orders. Since both totals are below eleven, none of those sequences has already ended the match. ThusFor a completed Sheila win with losses, the last game must be her eleventh win. The preceding games contain ten wins and losses, so their probability is , followed by one further factor . The allowed loss counts are , and these terminal events are disjoint. HenceThis is the match win probability with a fixed winning score, obtained by the negative binomial stopping argument. Constant marginal game-win probabilities alone would not justify the product without the usual independence assumption.
Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 2 11 b Solution by
Codex 0 2026-10-18
Normalize the Rayleigh distribution by substituting :For its sketch, the density starts at zero, is positive for , and tends to zero at infinity. Differentiation givesIt therefore has a single maximum at , with height .
The expected value isIntegrating by parts with makes the boundary term vanish and leaves . The Gaussian integral gives
Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 2 11 a Solution by
Codex 0 2026-10-18
Let mean control-group membership and the adverse event. Equal allocation gives , so the law of total probability gives . Bayes' theorem then givesThis is defined when . If both are zero, the conditioning event has zero probability and the stated conditional probability is undefined.
Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 2 10 b Solution by
Codex 0 2026-10-18
Integrate the probability density function over the specified interval:The endpoint inclusions make no difference for this continuous distribution.
Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 2 10 a Solution by
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Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 1 9 b Solution by
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Real points require , and the two branches areThis is a semicubical parabola, symmetric about the horizontal axis and with a cusp at the origin. The parametrization , traces both branches. Their limiting slopes at the origin are zero, so the common tangent direction is the positive horizontal axis, even though the curve has a cusp there.
The two real branches of the semicubical parabola and their cusp at the origin
. Details. Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 1 9 a Solution by
Codex 0 2026-10-18
On , the quadratic polynomial is positive. The required area is therefore its definite integral above the horizontal axis:The units are square coordinate units.
Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 1 8 b Solution by
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The second derivative is , so . By the second-derivative test, the stationary point is a strict local minimum, at . It is not a global minimum, since this cubic is unbounded below toward negative infinity.
Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 1 8 a Solution by
Codex 0 2026-10-18
Differentiate the polynomial and factor:The stationary points therefore have horizontal coordinatesFor a check, is negative at the first and positive at the second, giving a local maximum and a local minimum respectively.
Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 1 7 b Solution by
Codex 0 2026-10-18
This exponential function is positive everywhere, with , as and as . Its derivatives areIt is strictly decreasing overall, with a horizontal stationary inflection point at . A second, nonstationary inflection point occurs at , where . The only horizontal asymptote is toward positive infinity; the graph is not symmetric about the vertical axis.
The decreasing cubic exponential, its stationary inflection, and its positive horizontal asymptote
. Details. Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 1 7 a Solution by
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Where the original expression is defined, multiplication by givesThus the graph repeats with period and has vertical asymptotesBetween consecutive asymptotes the extended cotangent branch decreases from to , since . It passes through and .
It is essential to preserve the domain when simplifying a function. At , the original tangent is undefined. The finite limiting value is zero, so the graph has holes at , rather than actual zeros. The simplified expression extends across those points, but the original one does not.
Past exam of the mathematics course of the year 1 of the natural sciences course of the University of Cambridge 2014 Paper 1 6 b Solution by
Codex 0 2026-10-18
Interpret the stated side lengths as all eight edges of the square pyramid. The equal lateral edges put its apex above the base centre. The base-centre-to-vertex distance is half the diagonal, . The Pythagorean theorem therefore givesUsing the pyramid volume formula with a base,
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.
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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:
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