crashMATHS

By demand, a brand new 2nd GCSE revision maze has been added to the site. Find it at crashmaths.com/gcse-teaching-… #gcsemaths

@missradders See: en.wikipedia.org/wiki/Equation

@missradders ... satisfy the equality are called solutions of the equation.

Genuine question: simultaneous equations, variables or unknowns? #MathsConf25

@missradders I don't think they are terms that have a particularly formal definition, but my understanding is that it isn't incorrect to use the term variable, even when the equation is being or has been solved and the values of these variables have been found.

@MsSambrook Hi Tia - which booklet are you talking about?

@crashMATHS_CM do you have answers to the mechanics revision booklet you did last year by any chance? Tia

@MissAHughes8 @DirectorMaths @whisto_maths @mathsmrgordon @mathninja3 @Just_Maths @mathsjem @JenMaths We do! We have a variety of unseen mock exam papers for GCSE and A Level maths, and you can customise the content too. See: crashmaths.com/cm-mocks

Does anyone in the maths world know of any services that provide unseen mock papers? #mathschat please retweet if you can! @DirectorMaths @whisto_maths @mathsmrgordon @mathninja3 @Just_Maths @mathsjem @JenMaths

@mrenglishmaths @robotmaths @mrshawthorne7 NB it is interesting to see that we have to pick a convention for the square root function. If √x was allowed to be negative, we’d have something like this: 1 = √1 = -1 giving 1 = -1...

@mrenglishmaths @robotmaths @mrshawthorne7 have the space for two answers because that is not what the function is defined to do. However when just speaking about ‘square roots’, there is the option for 2 answers

Because I love a good maths twittter poll... Root 9 is? (More importantly, at what level, GCSE,a-level etc, would students be expected to give two answers? )

@PaulRodrigo2718 @Whitehughes Or y=|e^x - k|, k>0

@Whitehughes What example would you give of a curve that does cross its asymptote?

@robotmaths @jessica__sands @KerryDunton @PearsonEdexcel @EmporiumMaths @MathsNot I agree with everything you say; there are fundamental problems with the question but it is good that it is encouraging debate. This is an old resource, and I don't think it is still on the website. The website is being updated and there is a better version of these on there

@crashMATHS_CM @jessica__sands @KerryDunton @PearsonEdexcel @EmporiumMaths @MathsNot Thanks Crashy. My first problem with the table is it makes it look like the first category (tr) covers everything from 0 to 1 inclusive. The second is the data doesn't match the actual LDS for Heathrow 2015. While there are 7 tr values, there aren't 7 values between 1 and 4.

I'm sure I remember being told that students should replace trace with 0.025 when doing calculations with the @PearsonEdexcel A level Maths LDS but the textbook says 0. Can you confirm @EmporiumMaths @MathsNot

@robotmaths @jessica__sands @KerryDunton @PearsonEdexcel @EmporiumMaths @MathsNot ...a different point of view, eg "why is 0.025 a well chosen value"? In terms of Question 1, I may be looking at a different sheet as we have a few published, but the table is accurate I think. I do agree that 1.0 < r ≤ 2.0 is better but 1 < r ≤ 2 is still true

@robotmaths @jessica__sands @KerryDunton @PearsonEdexcel @EmporiumMaths @MathsNot If asked to use a suitable value in place of 'tr' in a data processing exercise, either the value they want you to use would be made clear or any well justified value would likely be accepted - eg 0 or 0.025 mm seem well chosen. Questions may also assess knowledge from...

@ygbjammy So essentially, the logic is 1. constrain the system so that any solution is not unique and 2. show that \vec{0} can be a solution for a suitable value of b (13). This then gives an infinite number of solutions

@ygbjammy ... if there are infinite number of solutions, then \vec{0} must be one of these. Looking at the symmetry of the inverse matrix, it is sufficient to require the third row to be 0, since the value of b we get makes all the rows 0. This is a solution, and with a=-3 it is not unique

@missradders |e^x - k|, k positive, should be an accessible/familiar counter-example for A level students!

Today’s heated hub conversation: can a function cross its asymptote? Thoughts?

@missradders Sorry I’ve used ‘terms’ loosely, but 3xb has two objects involved which is the pattern I noticed in their answers first^AK

@missradders I think they’re counting the number of terms in each case and using that as b in Q4. Similar for Q5 to get 6 (4 terms +2) and 8 (4 terms x 2)? Not sure about the 11 or 18 though...

Genuine question; what misconception is going on here? I promise the other kids I’ve actually managed to teach. 🙈

@JennyHillParker @vbmaths @DrFrostMaths @mathsjem We had ours written by @crashMATHS_CM - it was one of the only ways to get a cheat proof set of exams. Some great original problem solving questions too!