MolloyMaths

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@LikhweziMfenqe 2 күн бұрын

This is really helpful

@molloymaths1092 2 күн бұрын

Thanks. Glad it helps.

@Qiyuyang115 7 күн бұрын

thank you for keep loading the tutorial video!! it helps me a lot

@molloymaths1092 7 күн бұрын

You're welcome. Glad they help.

@adityasrivstava4449 8 күн бұрын

Thanks mann

@molloymaths1092 8 күн бұрын

You're welcome.

@RubatoBran 9 күн бұрын

At 10:14 it should be 306th day. Must have an error somewhere

@molloymaths1092 8 күн бұрын

Don't think so!! 5 is correct.

@kevinoreilly1 13 күн бұрын

where is minus 1/x^2 coming from ?

@kevinoreilly1 13 күн бұрын

in q6 part b i

@molloymaths1092 13 күн бұрын

@kevinoreilly1 When you differentiate Sin(1/x) you have to use the chain rule. Sin(1/x) becomes Cos(1/x). you then have to differentiate 1/x. 1/x is x^-1. Bring down the -1 to the front of x and reduce the power by 1 so we get -1x^-2. This is -1/x^2.

@simongibson6755 Ай бұрын

Hi there. Thank you so much for these videos. very helpful!

@molloymaths1092 Ай бұрын

You're welcome.

@MundiaMwiya Ай бұрын

Thanks for the explanation ❤

@molloymaths1092 Ай бұрын

You're welcome.

@teodorcornea7014 Ай бұрын

From the bottom of my heart, you are doing a service beyond a million thank yous, thank you for helping me to relieve some stress over the upcoming mocks

@molloymaths1092 Ай бұрын

Thank you. I'm glad the videos have helped. Good luck in the mock and LC.

@Thea-o5d Ай бұрын

keep up the good work these videos help so much👍

@molloymaths1092 Ай бұрын

Thanks. Glad they help.

@mondayjoyce Ай бұрын

Is there a pdf with the solutions

@molloymaths1092 Ай бұрын

I'm afraid not.

@FlatTopRob Ай бұрын

Soon as you demonstrated half the distribution curve, had to let out a little “wow”. Awesome stuff! Thanks for the derivation!

@molloymaths1092 Ай бұрын

Glad it helped. Thanks.

@Sierra-p3d Ай бұрын

If only I will be able to figure out I will have to use these methods on the day of the exams...

@molloymaths1092 Ай бұрын

Practice, practice, practice. Keep trying. It'll click in time.

@Sierra-p3d Ай бұрын

@@molloymaths1092 Will do my best, thank you sir.

@michaelkuha3263 Ай бұрын

great job

@molloymaths1092 Ай бұрын

Thanks!

@lobstermobster3648 2 ай бұрын

Very helpful and easy to follow, thanks.

@molloymaths1092 2 ай бұрын

You're welcome!

@yuri0568 2 ай бұрын

Thanks man! Honestly did not pay attention to math class for my entire schooling, so having to go through everything on my own. This helped a ton!

@molloymaths1092 2 ай бұрын

Glad they help. Good luck!

@katiequinn7186 2 ай бұрын

Where did 6/4y come from 14:57

@molloymaths1092 2 ай бұрын

(x + y)^2 = x^2 +2xy + y^2. It's the same in the question. You square the first term, You square the last term. You multiply both terms and double your answer for the middle term. Or use Pascal's triangle to expand. Or use the Binomial expansion method. Either way you get three terms when the power is two, four terms if the power is three, etc.

@danielcobban8755 2 ай бұрын

I thought I understood it until we added a 2Npi why do these appear isn’t it just cos pi raised to 1/3

@danielcobban8755 2 ай бұрын

Like why did it get used in this question and not all the other ones what indicator was there

@molloymaths1092 2 ай бұрын

@@danielcobban8755 When converting a Complex Number that's in rectangular form to Polar form, there is just one answer. You do not include 2nPi. If on the other hand you have to SOLVE a Cubic equation (as in this case), you have to allow for all possible solutions - in this case three solutions. So you have to write out the general form i.e. include the 2nPi.

@danielcobban8755 2 ай бұрын

@ if I’m understanding correctly if it asks for roots add the 2npi if it just wants say to the power of 9 don’t add the 2npi

@molloymaths1092 2 ай бұрын

@@danielcobban8755 Yes. If it's a cubic equation for example there are three roots. You use 2nPi - the general form to find all the roots starting at n = 0 etc. If you are raising a complex number to the power of three for example you don't.

@danielcobban8755 2 ай бұрын

@ thank you so much

@Shauna_OConnor 2 ай бұрын

If you multiplied (3+2i) by (1-i)^8 and got (5-i)^8, almost working backwards to your method, and then doing De Moivre's Theorem would you get the same answer? And if not, how many marks would you get?

@molloymaths1092 2 ай бұрын

Should work. How did you do the multiplication? Seems like a very long procedure.

@Shauna_OConnor 2 ай бұрын

@@molloymaths1092 Sub in values for initial geometric sequence and find an overall complex number. (5-i)^8 i think

@molloymaths1092 2 ай бұрын

@@Shauna_OConnor If you multiplied (3+2i) by (1-i)^8 you should get (48+32i). If you do it using a Geometric sequence when do you use De Moivre's Theorem? I think that they require you to do it the way that I've done it but I'd be interested to see your method in full.

@Shauna_OConnor 2 ай бұрын

Would theta not be 11 pie /6 because of its position in the 4th quadrant?

@molloymaths1092 2 ай бұрын

11 Pi/6 is the same angle as - pi/6

@Shauna_OConnor 2 ай бұрын

@@molloymaths1092 thanks

@danielcobban8755 2 ай бұрын

Why is x=p

@molloymaths1092 2 ай бұрын

You're given it as x in the question.

@David-Lambe 3 ай бұрын

Thanks for the videos they are making a big difference in my grades.

@molloymaths1092 2 ай бұрын

You're welcome. Glad they help.

@kitnamor 3 ай бұрын

Thank you so much!

@molloymaths1092 3 ай бұрын

You're welcome.

@padraigfitzpatrick762 3 ай бұрын

On the graph, your x axis shows the time of day starting at 00:00. But t is the time in hours starting from the first high tide. So shouldn’t P be 0? And the start of the graph (at midnight) be minus 2?

@molloymaths1092 3 ай бұрын

You are told in the question that p high tide. If you take the final formula 3.6 + 1.9Cos(0.5t) and put in for example 2 hours (i.e. at 4 am) you get 4.6 which is correct from the graph. The same if you put in -2 hrs (Midnight). You also get 4.6. t is the time from the first high tide which is at p.

@NeyVasconcellosJr 3 ай бұрын

Excellent job. Thank you, easy to follow. 🎉🎉🎉🎉

@molloymaths1092 3 ай бұрын

You're welcome.

@liamvorster7056 3 ай бұрын

how do you know what to do with each row?

@molloymaths1092 3 ай бұрын

You need to end up with 1, 1, 1, in the diagonal and the rest zeros. How you get there may be different to the way I got there.

@Reddglawer 3 ай бұрын

for the Θ part why is did you put -π/3? is the answer not 2π - π3 which is 5π/3?

@molloymaths1092 3 ай бұрын

The marking scheme allows for either one. They both get you to the correct answer. Conventionally, when converting from rectangular form to polar form, theta is between zero and Pi.

@Reddglawer 3 ай бұрын

@@molloymaths1092 I know that the marking scheme accepts both answers, I want to understand why both values are acceptable.

@molloymaths1092 3 ай бұрын

@@Reddglawer They're the same angle.

@Reddglawer 3 ай бұрын

@@molloymaths1092 thank you.

@IntegerFactoring 3 ай бұрын

So I’ve seen two comments wondering about why g(x) is set to K*exp(kx^2). So I’ll explain why. If you use the substitutions: h(z) = log(g(sqrt(z))) u = x^2 v= y^2 You get h(u+v) = h(u) + h(v) Where h(w) = aw+b are a class of functions that satisfy the property. If I remember correctly, there are other classes of functions that satisfy this property, but they are weird, I think pathological if I recall correctly, which I guess aren’t as “nice” as linear functions.

@padraigfitzpatrick762 3 ай бұрын

For b (ii), it says "find as a percentage, correct to 3 significant figures". So why take the significant figure approximation from 'i' rather than the percentage value. As in, use 1.654%. Maybe I'm being a bit pedantic!

@molloymaths1092 3 ай бұрын

I presume you mean parts (ii) and (iii) from b. Normally in these questions you would take the answer from the previous part of the question unless otherwise told. It would be harsh to penalise you for using the unrounded number but they may do so. I'm not sure but thanks for your comment.

@Jafilkhan. 3 ай бұрын

sortest path is SCGIT -->>34 Is it correct or not ply confirm me.

@ProsperChinonge-wq6if 3 ай бұрын

helpful

@padraigfitzpatrick762 3 ай бұрын

The square root of w^2 is plus or minus w, so you only need to find one value of w then just get the negative of that. That means you don’t need to write it in the generalised format and the question is much easier. Excellent set of videos, though!

@molloymaths1092 3 ай бұрын

Yes but it's part of a general procedure for higher powers. Thanks for your comment.

@kjoter 4 ай бұрын

thank you

@molloymaths1092 4 ай бұрын

You're welcome.

@caoilainndoyle2320 4 ай бұрын

these solutions are wrong. q 7 - look at the marking scheme. your answer is not correct.

@molloymaths1092 4 ай бұрын

Other than the fact that I didn't convert to minutes and seconds in part (e), I can't see what you are talking about.

@AmirmahdiAlinaghipour 4 ай бұрын

amazing

@nxtgamming3510 4 ай бұрын

Legend is learning 1 day before exam

@richardslater677 4 ай бұрын

You can do a general proof by contradiction to show that the square roots of all positive integers (that are not perfect squares) are irrational.

@I.am.nedzamba 4 ай бұрын

Thank you very much

@molloymaths1092 4 ай бұрын

You're welcome.

@SassouKhabou 4 ай бұрын

Thank you for this! Very clear and straightforward and actually makes Gauss-Jordan elimination fun!

@molloymaths1092 4 ай бұрын

Thanks. Glad it helps.

@musaabubakar4293 4 ай бұрын

Wow! Thank you so much for making me great

@molloymaths1092 4 ай бұрын

No problem. Thanks.

@tradingchris 5 ай бұрын

Not a gauss-jordan!

@molloymaths1092 5 ай бұрын

Yes it is! When using RREF it's Gauss Jordan Elimination. When using REF it's Gaussian Elimination. I have used RREF in this video. I think I mention Gauss Jordan at the end of the video. Thanks for the comment.

@valeriereid2337 5 ай бұрын

Thank you.

@molloymaths1092 5 ай бұрын

You're welcome.

@user-dy5uv8xv4k 5 ай бұрын

Vos explications sont tellement simples, j'ai le bac à passer et j'me fais une remise à niveau force à vous

@molloymaths1092 5 ай бұрын

Merci. Bonne chance.

@hybridtheory_69 5 ай бұрын

Can equation #7 be factorized any further into (x - 1)(2x + 5)?

@molloymaths1092 5 ай бұрын

Yes it can. The idea is to simplify the fraction so either way is fine. Thanks for the comment.

@Meatbrick 6 ай бұрын

Safe to say I couldnt understand anything past 9:00. Could you leave a trail of references and math topics that a student could look into to better understand?

@molloymaths1092 6 ай бұрын

You'll have to be more specific.