this was incredibly helpful, you explain things step by step and do not overcomplicate things. Plus you stick to the textbook methods which makes it easier to follow as i already know the methods you are using.
52:20 how come when you had the log on both sides you cancelled them down ? But when you had a sinx on both sides and we cancelled out the sin you said you were losing a solution? Are we still losing a solution when we cancel the log?? They’re both functions no?
Hey, this response is probably so late you don't need to know now but here it goes lol: The question is asking 'What values of x produce a negative y'? The numerator, 10, is constant. Regardless of the value of x the numerator is positive. The denominator, (x+1)³, can be negative or positive. If the denominator is negative, then y will be negative. So we can adapt the statement to test this. (x+1)³ < 0 x+1 < 0 x < -1 Therefore, when x is less than -1 then the denominator will be negative and thus y will be negative. It is not a less than or equal to symbol as 10/0 is undefined. Anyway hope that helped :)
It's to do with the rate of increase. If it was just e^t, then that would restrict the car to just go up in value by a factor of e (which is about 2.7) every year. Does that really make sense? At the start it would be 20000, then after 1 year it would 20000*e which is about 53000, then after 2 it would be 20000*e^2 which is about 148000 etc... Having the k there gives you more flexibility. Firstly, it gives the option of decreasing value (which happens to be what we want here - the value of the car is going down over time) - this would correspond to a negative value of k. Secondly, it can control the rate of decrease. e^(-t) would decrease much faster than e^(-0.1t) for example.
Yes. Multiply up by cos(theta) and put everything onto one side, giving 10sin(theta)cos^2(theta) - 9sin(theta) = 0. Then factorise out sin(theta) and set each bracket individually equal to 0
Put the integral into your calculator, what do you get? I don't know about you, but I have a Classwiz. When I put that integral into my calculator it evaluates the integral (i.e. gives me a decimal - in my case it gives me 2.98...), but that's not what we want, we want the ln form! And that's the general problem with the calculator. It wants to work out the numerical value of stuff, and is never going to give you an expression in the form aln2 + bln3. You need to realise that the examiners know you have an integral button on your calculator, and they will set the exams accordingly. That means that nobody can escape dem integrals! 😂
for Q2a) when it asks for one real root, how do you know that this is an intersection with y=cosx and not the root on the x axis? thanks for the video!!
Completely fine mate 👌 It's the same thing to write Ab^t or Ae^kt, because I can write e^kt as (e^k)^t. But e^k is just a constant to the power of another constant, which itself is just a constant! So I could write b = e^k here and it would be the same thing
Hi sir I have a question at 51:19. When u say R3-B=-R1 I don’t think I agree. When you say -B you do this because B would come out negative , but if you do -B then it makes it positive , so r3-B is the total area of those combined , and it would come out positive right. So why are you setting this equal to -R1. Surely it would just be equal to R1 as R1 is positive , and so is R3-B.
Good question! The value B itself would be positive. I'm not defining B as 'the integral between the origin and x=4', I'm just defining B as the area under the curve, which is positive. Then when I take the integral of the curve from 0 to 5.442, it would be made up of +R3 (area above the axis) and -B (area below the axis). Does this help clear things up?
For Question 12, part b, you use the differentiation of the previous function. but isn't this new function a modulus function so, the differentiatino wouldn't it be different? thank you for your time
Hi Sir, for question 11 the upper bound is 20 and lower bound is 5 so wouldn’t n be 15, not 16 ? I understand this is the trick of the question but I don’t fully understand year related sequence problems in general. Could you please explain?
The range does have those bounds but it can be equal to 5 and 20 as well. If you count 5 to 20 *including* 5 and 20 you will end up with 16. By subtracting them you miss one out Kinda easier to imagine if you want all numbers between 1 and 3 inclusive. You have 1, 2, and 3. If you just do 3-1 you only have 2 numbers and are skipping one out
For question 12c, shouldn't the equation h(t) be written in terms of t so 10e^-0.25t instead of using x and t in the equation because we are subbing in tan t=4? Also, your videos are so so helpful, thank you so much!!
It's small angle approximations, comes under "radians" if you're using pearson year 2 book. You know it's positive because in your intersection diagram the x value of the intersection is positive
The most general and easy way to think about it is 90% for an A*, 80% for an A, 70% for a B, 60% for a C etc... However this will vary slightly depending on the year, the exam board, the difficulty of that specific paper, how people performed on that specific paper etc, but a good general rule is 60% for a C 👌
You're so upbeat and have such a great attitude. Thanks for helping me study, but importantly also making me smile.
Great to hear it mate 🙏
revising for my whatever they are being called now in 2021. You are a godsend!
Good to hear, best of luck in your whatevertheyrecalleds!
yessss "whatever they are being called now" ughh so true I'm doing my mocks. so rubbish :/ btw good luck :)
I love your enthusiasm! You bring life to the questions and I actually enjoyed working out the questions alongside you
I think the 2019 paper for the edexcel maths was the hardest so far
yeah I hope so
@@passiv_5602 i have a feeling we are gonna get even harder paper, seeing the fm exam i am just praying our exam is easier
Question 6 and 8 are absolutely disgusting
@@itzdimi7569 I hope edexcel makes a wonderful paper on Tuesday, not like this one but I have a feeling we might get finished
@@rellaloli8548 same omds 😭
this was incredibly helpful, you explain things step by step and do not overcomplicate things. Plus you stick to the textbook methods which makes it easier to follow as i already know the methods you are using.
Super helpful mate trying the paper along side you and seeing my mistakes is perfect!
Glad to hear it mate, happy to help 🙏
52:20 how come when you had the log on both sides you cancelled them down ?
But when you had a sinx on both sides and we cancelled out the sin you said you were losing a solution?
Are we still losing a solution when we cancel the log?? They’re both functions no?
19:05 bro you’re literally a genius I’ve never seen that being done
He is wtf
Love your videos brother, constantly improving my ability to spot little tips and tricks, brilliant- all i can say!!
I love this guy
You are amazing at mathematics you have helped me so much for my mock exam Idk what I wud do without u much love from lindo
10:40
To get 10/(x+1)³ < 0
I’m aware if you start by multiplying both sides by the denominator you’ll get 10
Hey, this response is probably so late you don't need to know now but here it goes lol:
The question is asking 'What values of x produce a negative y'?
The numerator, 10, is constant. Regardless of the value of x the numerator is positive.
The denominator, (x+1)³, can be negative or positive. If the denominator is negative, then y will be negative. So we can adapt the statement to test this.
(x+1)³ < 0
x+1 < 0
x < -1
Therefore, when x is less than -1 then the denominator will be negative and thus y will be negative. It is not a less than or equal to symbol as 10/0 is undefined.
Anyway hope that helped :)
You are an absolute legend sir!!!!🤓
Can you please solve the 2020 papers?
for 31:45 I don't understand the reasoning for having constant k in e^kt as opposed to e^t
It's to do with the rate of increase. If it was just e^t, then that would restrict the car to just go up in value by a factor of e (which is about 2.7) every year. Does that really make sense? At the start it would be 20000, then after 1 year it would 20000*e which is about 53000, then after 2 it would be 20000*e^2 which is about 148000 etc...
Having the k there gives you more flexibility. Firstly, it gives the option of decreasing value (which happens to be what we want here - the value of the car is going down over time) - this would correspond to a negative value of k. Secondly, it can control the rate of decrease. e^(-t) would decrease much faster than e^(-0.1t) for example.
can you explain the bit at 25:26 again? Is there an alternative method?
Yes. Multiply up by cos(theta) and put everything onto one side, giving 10sin(theta)cos^2(theta) - 9sin(theta) = 0. Then factorise out sin(theta) and set each bracket individually equal to 0
For the integration on Question 13 why not just use the integration function on the calculator?
Put the integral into your calculator, what do you get? I don't know about you, but I have a Classwiz. When I put that integral into my calculator it evaluates the integral (i.e. gives me a decimal - in my case it gives me 2.98...), but that's not what we want, we want the ln form! And that's the general problem with the calculator. It wants to work out the numerical value of stuff, and is never going to give you an expression in the form aln2 + bln3. You need to realise that the examiners know you have an integral button on your calculator, and they will set the exams accordingly. That means that nobody can escape dem integrals! 😂
@@AITutor Right! i didnt realise that it was needed in the ln form. My bad.
@@ibrahimiqbal8649 It's definitely a valid question though mate, I'm sure many people were thinking the same thing!
SO HELPFUL what a legend
for Q2a) when it asks for one real root, how do you know that this is an intersection with y=cosx and not the root on the x axis? thanks for the video!!
For Q7 my equation was 20000x 0.8^t does this still get the marks
Completely fine mate 👌
It's the same thing to write Ab^t or Ae^kt, because I can write e^kt as (e^k)^t. But e^k is just a constant to the power of another constant, which itself is just a constant! So I could write b = e^k here and it would be the same thing
Hi sir I have a question at 51:19. When u say R3-B=-R1 I don’t think I agree. When you say -B you do this because B would come out negative , but if you do -B then it makes it positive , so r3-B is the total area of those combined , and it would come out positive right. So why are you setting this equal to -R1. Surely it would just be equal to R1 as R1 is positive , and so is R3-B.
Good question! The value B itself would be positive. I'm not defining B as 'the integral between the origin and x=4', I'm just defining B as the area under the curve, which is positive.
Then when I take the integral of the curve from 0 to 5.442, it would be made up of +R3 (area above the axis) and -B (area below the axis). Does this help clear things up?
@@AITutor right yeh thanks man. love ur enthusiasm. just waiting for u to upload some disgusting Qs/ the 2020 autumn papers
why is he called AI tutor, is his name allen iverson or is he just an actual AI
For Question 12, part b, you use the differentiation of the previous function. but isn't this new function a modulus function so, the differentiatino wouldn't it be different?
thank you for your time
Is it ok to say k increases by remains less than 0 for question 7c?
Could you do the specimen papers/sample papers? I lose most of my marks on sequence and series, logs and vectors. These videos are so helpful.
We'll see what we can do!
Sample papers here for you my friend! 🔥🔥🔥 ua-cam.com/video/_Kd-P6tcWbQ/v-deo.html
Hi Sir, for question 11 the upper bound is 20 and lower bound is 5 so wouldn’t n be 15, not 16 ? I understand this is the trick of the question but I don’t fully understand year related sequence problems in general. Could you please explain?
The range does have those bounds but it can be equal to 5 and 20 as well. If you count 5 to 20 *including* 5 and 20 you will end up with 16. By subtracting them you miss one out
Kinda easier to imagine if you want all numbers between 1 and 3 inclusive. You have 1, 2, and 3. If you just do 3-1 you only have 2 numbers and are skipping one out
@@scrumdum1 Thanks for the response, makes sense !
For question 12c, shouldn't the equation h(t) be written in terms of t so 10e^-0.25t instead of using x and t in the equation because we are subbing in tan t=4? Also, your videos are so so helpful, thank you so much!!
Somebody help!!what just happened in question 2. Did we even solve questions similar to this before!!!!! I'm panicking cause no I feel dumb
i dont get it either tbh😭
what topic is question 2b? also how do you know a is positive??
It's small angle approximations, comes under "radians" if you're using pearson year 2 book. You know it's positive because in your intersection diagram the x value of the intersection is positive
Hi ive got an as level mock for only pure maths next month and was wondering what mark out of a 100 would be a c roughly? , thanks
The most general and easy way to think about it is 90% for an A*, 80% for an A, 70% for a B, 60% for a C etc...
However this will vary slightly depending on the year, the exam board, the difficulty of that specific paper, how people performed on that specific paper etc, but a good general rule is 60% for a C 👌
@@AITutor thanks so much
@@AITutor for 2019 it was 55% for an A
why are you called AI tutor?
youre a legend bro
cheers man, nice work.
Thank you very much, you are a World Class Teacher and also handsome!
@@Leeko_TV innit xD that was so random