i cant thank you enough i have moved from foundation to higher and im going yr11 i was having such a hard time understanding this and you just taught me in a matter of minutes
When I type both of the fractions at 5:44 and 7:00 into my calculator, it gives me totally different answers than to what's shown. Please could you offer some help as to why that could be because I am really stuck on that for the time being
Thank you for explaining however I have one problem, when I type the exact same formula on the calculator, I get a whole different result and it's the same thing with all the other exercises I've done...
@@1stClassMaths But those are multiplying, so can't they be separated, like you did in the next step when 2bcCos(C) was left alone so we moved Cos(C) to the other side?
You probably want to not think about things "shifting" or "moving" as this causes confusion. When rearranging we must do the same thing to both sides. If you were to try to remove the CosA from the right hand side at the start you must divide both sides by CosA. This would lead to a^2 / cosA = b^2 / cos A + c^2 / cos A - 2bc As you can see we no longer have cosA with the 2bc but we now have cosA in many other places that we do not want it. What we need to do is isolate the term with the cosA in it, which is -2bcCosA. We do this by adding 2bcCosA to both sides (and also subtracting a^2 from both sides).
I wonder why is this formula is similar as this formula (b-c)^2 i think there might be some relationship There's just add cos(A) with -2bc This is suspicious
Hi .Answer I'm getting at 7.31 is 69.62591067.I've checked that calculator is in degrees.I get the same answer using an online scientific calc. Please help
i cant thank you enough i have moved from foundation to higher and im going yr11 i was having such a hard time understanding this and you just taught me in a matter of minutes
Glad to be of service!
@@1stClassMathsi'm in 9th grade gotta do this already and the trimester is barely mid term.... I can't imagine 11th grade
@@fast9952 you better start imagining it y11 is stressful 😭
hi what did you get in ur mocks if your comfortable telling as i've moved from foundation aswell
@@fast9952year 9??
I cannot thank you enough. Listening to this in class helped me so much with learning such a hard concept in year 11
thanks for making me understand this in then minutes, you are incredible
You are so welcome!
just wanted to leave a huge thank you, I've been crying all day thinking i will never understand the exam material until i found this video
No problem at all. I appreciate maths is not always the easiest subject but with time and practice you can get there. Good luck for your exam.
Yessss tyyy I have an exam tomorrow and I had no clue until I found this 😊😊🎉
good luck in ur exam
mines in an hour 😭😭 watching this to learn how to do this
same lmao
One hour is crazy did you pass?
How did your exam go
This channel is underated
Thanks! This comment is underrated.
tysm this channel is so underrated
Thank you so much. You are indeed the best person on this earth and u deserve the whole worlds love
Thanks. Might be some slighly better people though!!
Thanks for making me understand a formula which was difficult for me to understand :)
this deserves more likes
Cheers!
thank you , this video is really helpful!!
thanks i will pass my exams
Thank you my brother my igc is soon and i forgot this formula
When I type both of the fractions at 5:44 and 7:00 into my calculator, it gives me totally different answers than to what's shown. Please could you offer some help as to why that could be because I am really stuck on that for the time being
Hey. You probably have the wrong angles mode set. Check if your calculator is in degrees mode.
ah yeah thanks man my bad @@1stClassMaths
thank you very very much, it helped more than enough:))
W for explaining it so well thank you so much❤❤
Thank you for explaining however I have one problem, when I type the exact same formula on the calculator, I get a whole different result and it's the same thing with all the other exercises I've done...
Hi your calculator is most likely set to the wrong angle unit eg radians.
@@1stClassMaths Yes thank you, I just figured it out
Always test sin 30 as you want it to be 0.5 😄
Thanks man i got exam in a month
Can you please post a video on quadratic expressions i have a exam after tomorrow plz help
Grazie prof.❤
But when changing the formula to find the missing angle, why don't we shift COS(A) directly to the other side?
Without the 2bc you mean?
If so you cannot do that because it is all one term -2bcCos(A).
@@1stClassMaths But those are multiplying, so can't they be separated, like you did in the next step when 2bcCos(C) was left alone so we moved Cos(C) to the other side?
You probably want to not think about things "shifting" or "moving" as this causes confusion. When rearranging we must do the same thing to both sides. If you were to try to remove the CosA from the right hand side at the start you must divide both sides by CosA. This would lead to
a^2 / cosA = b^2 / cos A + c^2 / cos A - 2bc
As you can see we no longer have cosA with the 2bc but we now have cosA in many other places that we do not want it.
What we need to do is isolate the term with the cosA in it, which is -2bcCosA. We do this by adding 2bcCosA to both sides (and also subtracting a^2 from both sides).
@@1stClassMaths Thanks a lot! 😀😀👍👍
Thank you 👍🏻
so USEFULL!!!!
Thanks ❤️
Your a legend
no you
How did you cancel a² from both sides when there was only one?
It only cancels from one side. The other side introduces - a^2
does it matter if we put our answer in a different decimal place like 2 dp if they don't specify?
Nope you will be ok. I’d go 1 or 2 dp for most if it doesn’t say.
usually the degree of accuracy is mentioned on the front of the paper. its safest to follow that one!
I like it too much😍
FINAL MATHS EXAMMM🎉🎉🎉🎉🎉🎉
When to use cosine rule as opposed to sine rule ?
Explains at the end of the video.
@@1stClassMaths is this for gcse math or gcse further math?
hey my teacher taught us cosine rule as
a²= √b²+c²-2abcos a 1:06
What would be a = rather than a^2 =
1st class math = many maths teachers at school and 1.30 hours in 10 minutes
LIFE SAVOR THANBK YOU
YOU'RE WELCOMBE
paper 3 predicted paper should be the best one!!!
Would this ever come up in a non calculator?
Yes. Quite possibly using an exact trig value like cos30, cos45, cos60 or even cos120.
love u
I wonder why is this formula is similar as this formula
(b-c)^2 i think there might be some relationship
There's just add cos(A) with -2bc
This is suspicious
everything in maths is related coming from a university student, its all connected in subtle ways
❤❤jawad. T
Hi .Answer I'm getting at 7.31 is 69.62591067.I've checked that calculator is in degrees.I get the same answer using an online scientific calc. Please help
You are not typing in the negative sign.