Your videos are amazing! Literally all the revision I did for my gcse maths was watch all of your grade 9-4 maths videos on 1.5x speed the night before each paper. I managed to get a grade 9! Thank you 😊
lol you dont need to do that, this is me after the exams and i'm likely to get a 8, at least i think but i defo get 7. guys doing gcse do lessons and follow it up wiith th30 min practice on that topic in school, if your school is good, then just do papers day before exams. No joke its wt i did and a 7 is defo, the papers are easy, just make sure you practiced all topics.Wish me luck, 3 more exams than 90 days holiday or so then ill see if i get 7 or 8. RIP me if i get 6 or 5 LOOL
im not going to lie this helped me a lot its 3am in south africa right now and im writing math in a few hours#finals keep doing what youre doing liked commented and shared
For the right angle in a semicircle question can you just do O = 180 (angle on a straight line equals 180) so ABC = 90 because angle at the circumference is half angle at the center?
@@haaris8053 No it is proof. The semi circle theorum is just a special case of the angle at the circumference one Since you've already proved the previous one there is no need to prove it a different way, thats how all proofs work.
At the moment, the only place where I am losing marks is in the hard problem solving / proofs questions (the ones at the end of the paper that most people aren't able to complete). How would you recommend revising harder problem solving questions in general, given that there isn't much time left and the questions could be based on seemingly anything?
For "Prove that opposite angles in a cyclic quadrilateral sum to 180°", Why couldn´t you use the circle theorem "The angle at the circumference in a semi-circle is 90°"?
Thanks, i've seen proof questions come up in this specification but if it's not necessary i've got a better understanding of them thanks to you anyway.
Just a quick question, thanks for these videos btw , what software and hardware do you use to write your answers to these exam papers when making these videos? Atm I am printing past papers, but I would like to do them online like you. Thanks!
When asked to prove the 2 angles in the same segment are equal, would we have to show all the proof for 'angle at the centre is double the angles at the circumference'?
Good question: it hasn't been a GCSE yet. It is probably likely to be a part b question where you prove the angle at the centre is double the angle at the circumference in part a.
Assuming chord AB cuts radius OC: Construct the diameter BD, we have ∠DOC=∠OBC+∠OCB =∠OBC+∠OBC =2∠OBC Also, ∠DOA=∠OBA+∠OAB =∠OBA+∠OBA =2∠OBA Note that ∠AOC=∠DOC-∠DOA =2∠OBC-2∠OBA =2(∠OBC-∠OBA) =2∠ABC Same method for the case chord BC cuts radius OA.
he factorised 2 out of the while equation to get an answer for 1/x and 1/y which was 90. This was then used to prove that since =180-(1/2x + 1/2y) you can sub the 90 into the equation as 90 also equals 1/2x+1/2y. The overall answer would then be 90 as 180-90=90
I know im a good few years late but this is the exact diagram/shape the question is: A, B, and C are points on the circumference of a circle, centre 0. AOB is a diameter of the circle. Prove that angle ACB is 90° You must not use any circle theorems in your proof. any help?
can you please help me with something, i didnt understand why you used 90 degrees in the alternate segment theorem proof and said as its because angle in a semi circle is 90 degrees at 12:40 please help exams are very soon. Thank you
thank you sir but how do we know that the angle is 90 degrees as there wasnt a tangent meeting the radii. i wasnt really sure how you obtained the angle. Thank you very much for taking the time out to help.
We drew on the diameter - we know it is a diameter. Then we are just using what we already know about a diameter - that it meets a tangent at 90 degrees and the angle in a semicircle is 90 degrees.
@@abdetaheri5522yes it’s a theorem, any angle in a semi circle will be 90 degrees. just realised I’m 5 years late and u probably don’t have the stress of math anymore 😭😭
Kills me how excited he sounds as he proves each one I actually love it
Freesciencelessons + Maths Genie = 4 Grade 9s
ikr 😂😂😂
no cap
+ mrbruff=6 grade 9s
Um, I actually am a year 6, so yeah.
@@mathlegendno12 I’m in year five xd
Your videos are amazing! Literally all the revision I did for my gcse maths was watch all of your grade 9-4 maths videos on 1.5x speed the night before each paper. I managed to get a grade 9! Thank you 😊
+Zainah Sadak thank you and a massive congratulations!
Use 2x >:D
Double the speed, double the maths!
for real?
woah lucky
lol you dont need to do that, this is me after the exams and i'm likely to get a 8, at least i think but i defo get 7. guys doing gcse do lessons and follow it up wiith th30 min practice on that topic in school, if your school is good, then just do papers day before exams. No joke its wt i did and a 7 is defo, the papers are easy, just make sure you practiced all topics.Wish me luck, 3 more exams than 90 days holiday or so then ill see if i get 7 or 8. RIP me if i get 6 or 5 LOOL
im not going to lie this helped me a lot its 3am in south africa right now and im writing math in a few hours#finals keep doing what youre doing liked commented and shared
Dude almost exactly the same. South African. its 3PM and Maths is tomorrow
How was it?
Riyadh Ul-Hoque Yea I wonder
i'm going to download most of your videos and watch them on the bus to school
Thank you so much. This is so helpful.
There are some simpler methods but this still really helped
Thank u sooo much
Really helped me
Should have seen this channel sooner ❤️❤️❤️❤️😍
good teaching. I have been using the website since year 7 (i am in year 8 now) and this helped me to understand and remember the proofs.
Why the hell are you doing circle theorem proofs in Yr 8
@@bucepheluss ahhahah obviously not year 8 unless hes a child genius
Bangout
For the right angle in a semicircle question can you just do O = 180 (angle on a straight line equals 180) so ABC = 90 because angle at the circumference is half angle at the center?
That's verification not proof
@@haaris8053 No it is proof. The semi circle theorum is just a special case of the angle at the circumference one
Since you've already proved the previous one there is no need to prove it a different way, thats how all proofs work.
@@miikey_lol but in a real paper there will probably one of the questions, there wont be a previous one
BARE NEEKS HERE
Hey! Do we need to learn all of these proofs for the GCSE Edexcel Maths 9-1 exam? Will there be a proof question on circle theorems in the exam?
If you are aiming for the top grades you need to learn them. There is no guarantee it will come up - but it could.
At the moment, the only place where I am losing marks is in the hard problem solving / proofs questions (the ones at the end of the paper that most people aren't able to complete). How would you recommend revising harder problem solving questions in general, given that there isn't much time left and the questions could be based on seemingly anything?
The best thing to do is to make sure you understand all of the topics and practice all of the past paper questions.
For "Prove that opposite angles in a cyclic quadrilateral sum to 180°", Why couldn´t you use the circle theorem "The angle at the circumference in a semi-circle is 90°"?
Hi, are these the only proofs that will come up? If i memorise them, will I be good for the exam?? Thanks!
These are good ones to know. But just memorising won’t make you good. Answer a variety of different questions about proofs to test your knowledge.
Are there more proof videos on this topic for the other theorems or aren't they necessary to know for edexcel?
These are the ones required for the new specification (first exam 2017). For this year you do not need to prove the circle theorems.
Thanks, i've seen proof questions come up in this specification but if it's not necessary i've got a better understanding of them thanks to you anyway.
Just a quick question, thanks for these videos btw , what software and hardware do you use to write your answers to these exam papers when making these videos? Atm I am printing past papers, but I would like to do them online like you. Thanks!
He gets it from his own website, the maths genies website, I think
When asked to prove the 2 angles in the same segment are equal, would we have to show all the proof for 'angle at the centre is double the angles at the circumference'?
Good question: it hasn't been a GCSE yet. It is probably likely to be a part b question where you prove the angle at the centre is double the angle at the circumference in part a.
On (6:15) why do you plus it?
for theorem 1, if centre o is not inside triangle ABC, how don you prove it?
+anan zhang You could always draw the centre on. Every circle has a centre.
Assuming chord AB cuts radius OC:
Construct the diameter BD, we have ∠DOC=∠OBC+∠OCB
=∠OBC+∠OBC
=2∠OBC
Also,
∠DOA=∠OBA+∠OAB
=∠OBA+∠OBA
=2∠OBA
Note that
∠AOC=∠DOC-∠DOA
=2∠OBC-2∠OBA
=2(∠OBC-∠OBA)
=2∠ABC
Same method for the case chord BC cuts radius OA.
Legend
On 7:24 how did -1/2x - 1/2y turn into -(1/2x + 1/2y) Im so confused
Nice, very helpful Sir!
Since when did Anthony Joshua do math tutorials?
allroundlad 😂😂😂
That wasn't even funny
he doesn't sound anything like AJ, what you on? lol
I have a bellend
Why did you half x+y=180 at 6:53 ?
he factorised 2 out of the while equation to get an answer for 1/x and 1/y which was 90. This was then used to prove that since =180-(1/2x + 1/2y) you can sub the 90 into the equation as 90 also equals 1/2x+1/2y. The overall answer would then be 90 as 180-90=90
I know im a good few years late but this is the exact diagram/shape
the question is:
A, B, and C are points on the circumference of a circle, centre 0. AOB is a diameter of the circle. Prove that angle ACB is 90°
You must not use any circle theorems in your proof.
any help?
Is it Mr Senessie?
Good video
Paper one tomorrow!!!
lmao the boys same
sometimes i feel like he's shouting at me for not understanding it
me too lol that British accent also is terrible haha
seems like the king speaking to one of his servants
can you please help me with something, i didnt understand why you used 90 degrees in the alternate segment theorem proof and said as its because angle in a semi circle is 90 degrees at 12:40 please help exams are very soon. Thank you
We use the fact that the angle in a semi circle is 90 degrees to prove the alternate segment theorem.
thank you sir but how do we know that the angle is 90 degrees as there wasnt a tangent meeting the radii. i wasnt really sure how you obtained the angle. Thank you very much for taking the time out to help.
We drew on the diameter - we know it is a diameter. Then we are just using what we already know about a diameter - that it meets a tangent at 90 degrees and the angle in a semicircle is 90 degrees.
so an angle inside any semicircle is always 90 degrees?
@@abdetaheri5522yes it’s a theorem, any angle in a semi circle will be 90 degrees.
just realised I’m 5 years late and u probably don’t have the stress of math anymore 😭😭
Its time
Who's watching this for homework
hi
super
oh yeah yeah