This question deserves to be the most hated problem of trigonometry

@itsmeadi...2006

9 ай бұрын

Phir sir ne kya bola wahi to bola hai 🙄

@aakritkatyal9135

8 ай бұрын

4 step mein hogaya 😂

@shoyo_Ishida

8 ай бұрын

Naa!!

@aakritkatyal9135

8 ай бұрын

@@shoyo_Ishida solution chaiye

@shoyo_Ishida

8 ай бұрын

@@aakritkatyal9135 noop!!

Long but predictable method: sin (kpi/m), k=1..n are roots of equation sin(mx) = 0. So we expand sin(mx) in powers of sin(x) to get a polynomial equation in sin(x) of degree m. For m = 7 we get: sin(7x) = -64sin^7(x) +112 sin^4(x) -56 sin^2(x) + 7sin(x) =0. We can eliminate sin(x)=0 as solution, so the products of the remaining 6 roots is 7/64. This product is square of the required quantity.

@MyOneFiftiethOfADollar

8 ай бұрын

Did you "predict" the method prior to looking at the solution?

@Aditya_196

7 ай бұрын

Yeah bro same 😂 I once was curious and derived sin5x , 7x 9x 11x and those r some neet results if u want an interesting question check this .. what is the coefficient of last 3rd term of sin101x given that it's expansion is organised on the basis of descending order of powers of sinx ... Sayd question smjh me aagya hoga kya bol rha .... Actually mein general term ka coefficient khoj rha tha nahi mila but kuchh terms me pattern mila

@marrythebun-bun2501

7 ай бұрын

Hey please tell which theorem or Formula you have used, please tell the name 😢

@user-wd7yy2fm7g

5 ай бұрын

We can use complex numbers where w = cos(2pi/n) where w is nth root of unity

very well explained and nice approach. thank you!

Maza aa gaya sir, Definitely looking up for more such videos❤

Sir, i saw your video on the same problem and the next morning when i was searching for the video, i didn't find it anywhere, not even in my history, but then i thought that you might have deleted the video. Thanks for re uploading the problem.

@nishantpatriot3297

9 ай бұрын

Same with me😅

"BHANNAAAAT IS A ICONIC WORD" LOVE YOU SIR❤❤❤

Good evening sir.Sir pyq solving videos please

Req to you sir..pls start PYQ solving of last 3-4 years Maths

In general , it can be proved using complex numbers that: multiplication of 'N' terms of sines where each acute angle is in A.P. such that the first term is equal to common difference and last term is just less than π , is equal to (N+1))/2^(N). In the question in this video , let the value to be determined be X . Then , X²= sin(π/7)sin(π/7)sin(2π/7)sin(2π/7)sin(3π/7)sin(3π/7) Now using sin(x) = sin(π-x) , we have , X^2 = sin(π/7)sin(2π/7)sin(3π/7)sin(4π/7)sin(5π/7)sin(6π/7) The last equation follows the formula above , hence , X^2 = 7/2^6 = 7/64 . Take square root and you get your answer.

@vansh61595

9 ай бұрын

What should I put in the value of N

@benYaakov

9 ай бұрын

@@vansh61595 As written above , N is the number of terms.

@vansh61595

9 ай бұрын

Acha , thik h

@shlokpatel2472

9 ай бұрын

Hello :) I wanted to know how you came to know about this identity, because I am halfway through my 11th std., starting the chapter 'Circles' tomorrow, and I never came across such an identity while studying the two trigonometry chapters in the past. Thanks.

@aryannagariya6027

9 ай бұрын

Thank you for this trick

As a matter of fact sir , I have solved this problem during my JEE days and have come to IIT BHU after qualifying JEE23 . Thank you sir for bringing out such problems

@mananluthra6831

9 ай бұрын

Hey did you solve this by this method only ?

@itsshubh3430

8 ай бұрын

Sale flex maar. Rha h tu

@susmitadutta1029

8 ай бұрын

@@itsshubh3430 If he really did this tough problem all on his own he can flex and deserves the honour,kudos to the guy👏👏

@rajcr877

8 ай бұрын

Congrats bro❤

@mayurgaming347

7 ай бұрын

Q@@😊@😊

Well explained sir!! I appreciate your effort 😊👍 But sir ,,i have an another excellent approach,,which is luckily a brilliant and time saver approach for this particular question!! We have a formula ,,,sinπ/n .sin 2π/n .sin3π/n ... .sin (n-1)π/n = n/{2^(n-1)}. In this particular problem we have value for sinπ/7 sin2 π/7 ...sin6π/7 = 7/(2^6).. Now we let us assume sin π/7...sin3π/7 =X .then the next three terms can be transformed in terms of Series of X.as eg:-sin4π/7 =sin 3π/7..now the series become X^2 in LHS...now apply root both side .we get value as √7/8.. Its so simple,,can be done within 4-5 lines😊😎🔥🤘 Lets have a look to my approach! Hope u like it !!. Thankyou! Radhe radhe🙏

@shauryagupta3644

9 ай бұрын

Could you pls share with me a link for the proof of this formula, or just hint me the approach to prove it? Thanks

@shyamaldevdarshan

9 ай бұрын

​@@shauryagupta3644i appreciate your curiosity 😊!! And thankyou for read my approach 😊 . To be honest ,,this formula is not related to intermediate level directly!! And the proof is so lengthy ,you have to use eulers identity ,concept of limit ,and little bit use of complex no. Yeah iam also an iit jee aspirant right now😊 so ,no doubt you can understand the whole proof almost ! But this will worthless for u right now !! The result is important ,,so plz try to keep that result in mind ! Remember,,you cant use this formula in every situation,,the major condition is the coefficient of π in last term is 1 less than the denominator !!and the product should be continuous!! Further modification in this formula led to the result of "Riemann integral ". But still you want to know the proof ,,i have done an effort in searching the video you need to get the proof . Iam providing you link ,,you can chek it out!😊👇 kzread.info/dash/bejne/moVplZSMmsXeftI.htmlsi=auUbzdDu8AipVGw_ This contain the proof u want,,and given by any university professor !!👍. Once again ,i say ,,result is important!! Thankyou to love my approach!!😊👍 Radhe radhe 🙏

@timewalkwalker

9 ай бұрын

@@shyamaldevdarshan thanks I applied without knowing proof definately gonna learn proof after my complex number course.

@shyamaldevdarshan

9 ай бұрын

@@timewalkwalker welcome! Yeah sure! You can learn😊👍 Radhe radhe🙏

@atharvsalunke878

9 ай бұрын

Yes

why video was deleted and reuploaded sir?

Very nice sir. Quite inspirational solution

Super explanation sir 👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻🥳🥳🥳🥳

sir!! PW kyu chhoda ??

sir have very fast solution for this with complex no there is a trig identity of sin(pi/n) *sin(2pi/n) .... *sin((n-1)pi/n) = n/2^n-1 now keep n = 7 and now sin 4pi/7 is same as 3pi/7 and so on therefore ans = sqroot(n/2^n-1)

You are really a great teacher who can turn the most hated question to most loveliest one.

I have created formula see here for n=7 x=√7/8=} x^2 = 7/(8^2) And for n x^2=n/(2^[n-1]) ...😊

@Ayush-yj5qv

5 ай бұрын

Yeah easiest method

Appriciate for those student who solved. This question 😮

@MehtabHussain-vh3bl

9 ай бұрын

Bruh it's a basic question 🤖

@nikhildhanotiya5312

9 ай бұрын

​@@MehtabHussain-vh3bljee also ask basic question

Sin m^n=? ( No expansion, should be FINITE SERIES.)

Sir apse defense ka preparation krna hai kaise kre ❤

Good explanation sir 👏🏻.. but we can also solve this by following method Cosπ/7.Cos2π/7.Cos(π-4π/7) = Cosπ/7.cos2π/7.cos4π/7 =Sun(2.4π/7)/2³.sin(π/7) =Sin(π+π/7)/8sinπ/7 =Sinπ/7/8sinπ/7 =1/8 Thankyou!!!!

@mrstrange15yp

11 күн бұрын

Buddy don't u think ki tumhare method se answer -1/8 aaega because cos(180 - x ) is -cos(x) 🤔

Can also be done by complex no

Good qustion sir jeee namste🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏

Nice Explanation Sir. but I have another approach for this question as we know that CONTINUED PRODUCT(k=1 to n-1) sin(kpi/n)=n/(2^(n-1) HERE S= sin(pi/7) x sin(2pi/7)x sin(3pi/7) S=sin(6pi/7)sin(5pi/7)sin(4pi/7) =>S^2 =CONTINUED PRODUCT(k=1 to 6) sin(kpi/7)=7/2^6 =>S= sqrt(7)/8 HOPE U LIKE IT!! THANK YOU

@benYaakov

9 ай бұрын

Yes. It's a general formula which can be easily proved using complex numbers and a little bit algebraic manipulations.

@harashisharora1521

9 ай бұрын

This is exactly what i thought when I saw this.

@user-dd6cu2zw9c

9 ай бұрын

Can we get in touch please I think u can help me in mathematics.

@Player_is_I

9 ай бұрын

Your solution seems to be based on an interesting topic can you tell me more about that and for me there are some things that are unclear in your solution like how is s is equals to 2 products which are different I mean can you elaborate your solution

@benYaakov

9 ай бұрын

@@Player_is_I First, it's S^2 . Note that after squaring, each terms on RHS appear twice so that now we have a pair of each term which was present in S. Now , take exactly one term of each pair and use the identity sin(x) = sin(π-x) to get the desired product.

Reupload?

Sahi bola sir, formula hai sara yaad pr question nhi bn pata mere yaar

We love you sir❤

Can u please solve this question using quadratic equations/polynomials?

Sir please solve jee main 2023 1st feb shift 2 sequence and series question 🥺🥺🥺

Different approach - for series that is in product and is in form of sin theta we can use √2n+1/ 2^n . N - no of terms

@user-rf6ly9lk3s

8 ай бұрын

Use of complex no

@biriyanilover5596

5 ай бұрын

Abe chup gawar

Sir wat is math?

Sir please derive formula . I always mug up and can't understand relationship between the formula . √( s . S- a . S- b. S- c)

@mamtamittal3051

9 ай бұрын

Just search for derivation of Heron’s formula

@neerajprajapati3852

9 ай бұрын

It's easy you can find so many videos on it in English and may be in Hindi too

Wow! nobody will mind even if you also declare it as the most hated question in JEE level.

As a student of 10th class, I think trigonometry is used more in making questions harder , instead of finding length of a building.😂😂😂 Edit:Oh my god mai toh famous ho gya.

@prabaln4752

8 ай бұрын

Yes you thinks😂 correct

@skies_anuj

8 ай бұрын

Bilkul shi pakdo ho munna

@nirmalsurendranmenon7049

8 ай бұрын

😂😂😂😂😂

@heemensu

8 ай бұрын

it will make your analytical and critical thinking stronger... which are basics of logic development

@BeastModeWorkout24

7 ай бұрын

No, we use trigonometry in physics at an advanced level, therefore these difficult problems help us in that way.

Kya sir ne yeh video doobara post kra hai isse pehle yeh video sir ne kya post Kiya tha jo delete kr diya tha koi batao

why are we not considering the negetive counterpart of x?

The basic orthogonalality of sine waves is demonstrated here.

Excellent sir Thanks

Sir wbjee k liye kuch class hota to acha hota

2 ko 4 time multiply karne se 8 kaise hoga sir.

Bekar Sin ko cos me covert karo aur CosA cos2A cos4A....= sin2n/2nsina

power of aman sir- only 525 views and 106 likes❤‍🔥❤‍🔥❤‍🔥❤‍🔥🔥🔥🔥l

@subhadraprasad7676

9 ай бұрын

ध्यान से देखो😂

Sir ne bhot bade tarike se karvaya hai

There's one more method ∏^n−1k=1sin(kπ/n)=n/[2^(n−1)] we need to find sinpi/7.sin2pi/7.sin3pi/7 but to use the formula Given above we need to have 6 terms as k goes from 1 to 6 we also know that sin(pi-pi/7)=sin(6pi/7), sin(pi-2pi/7)=sin(5pi/7), sin(pi-3pi/7)=4pi/7 so we can say that [sin(pi/7).sin(2pi/7).sin(3pi/7)]^2 = ∏^6 k=1sin(kπ/7)=7/[2^(6)] so now we can take root on both the sides and get our answer as root 7/ 8

@MathsStar-qo1fn

9 ай бұрын

Awesome ❤

@dexroner

9 ай бұрын

Ans the proof of that formulae comes from complex numbers

@slimshadyff7848

9 ай бұрын

Can you please explain that to me 😅

@hretz

9 ай бұрын

@@slimshadyff7848 explain what? We only need to use the formula for this method, but the problem is most of us aren't aware of this formula. To calculate answer using the formula we need to make sure that we've 6 terms as the formula requires us to use from k=1 to k=(n-1) here n is 7 so k will be 6. Rest is basic, sin(pi-x) = sin x as second quadrant sinx is positive

@ad59986

9 ай бұрын

​@@hretzbro pls can you give name of the formula so that i can learn it .

5[1.96-sin^2{(cos^-1 (0.02)}° ] find the value of it . Challenge to you sir 😊😊😊.

U teach so well that MATHEMATICIANS will try to learn from uuu❤❤❤...

Sir kya ye question class 10 ke liye bhi hai

Sir sin(2pie/7)=sin(5pie/7) As we take 7@=(2n-1)pie We can make sin4@=sin3@ Expanded to °4cos@(1-2sin²@)=3-4sin²@(because sin@=0 is rejected) °then squaring both sides 16(1-sin²@)(1-2sin²@)²=(3-4sin²@)² °-64sin⁶@+128sin⁴@-80sin²@=9+16sin⁴@-24sin²@ °64sin⁶@-112sin⁴@+56sin²@-7=0 (is the equation in which if we take roots in form of sin²@, roots are sin²(pie/7),sin²(3pie/7) and sin²(5pie/7)) Lets comment on the values for all three angle sin give positive value ) From equation produts of roots in form of sin²@: sin²(pie/7)sin²(3pie/7)sin²(5pie/7)=7/64 Then sin(pie/7)sin(3pie/7)sin(5pie/7)=square root (7) /8 Sir I did this please see this one time sir .

You are the best guruji, thanks for the question practices ❤❤

अतिसुंदर❤

Maza aagaya sir but itna time kidhar hai solve karne ke liye ek question ko

Wonderful !

Very easy question of complex no.

As this is a IMO problem.............So This should be one of the hardest problem....

Sir apke questions ❤❤❤❤

Maturity is when you use calculator and get something different from √7/8 😂

Solved it...!... Loved the problem... I tried straight for two days for it 😂

Khatarnak question

sir 3 step ma aap ye jo tod te ho ye samaj ma nahe aata ha jesa ke aao ne 4π/7 ko 3π/7 likh diya 😢

Can also be done by complex no.

For such ques....Complex no. God

Loved it ❤

Complex numbers se kijiye alag swaad aayega. (use 7th root of unity)

@UttamSingh-i1x

7 сағат бұрын

Bro kaise

@UttamSingh-i1x

7 сағат бұрын

Kaise Bhai thoda hint batao

Mast hai sir

When we got 8xy=x, why can't we do this to find x 👇 8xy-x=0 x(8y-1)=0 x=0, y=1/8 It would've been much faster

@adarshsubramanian9560

7 ай бұрын

wrong if y=1/8 x can be any value

@yxsh5033

7 ай бұрын

@@adarshsubramanian9560 bro xy = x/8 wat are you talking about

@adarshsubramanian9560

7 ай бұрын

@@yxsh5033 For example if y=1/8 then if u take x value as 1 then also equation is satisfied

@avtar0079

4 ай бұрын

because x is not equal to zero

5:20 x zero nahi ho sakhta aapne kaise judge kiya sir? Plz batadijiye.

@neerajprajapati3852

9 ай бұрын

Kyunki sin. 0 180 360 me hi zero hota hai baki jagah nahi

@wipergaming1448

9 ай бұрын

​@@neerajprajapati3852 bhai lekin x toh multiplication of sin fn hai toh vo zero bhi ho sakhte hai.

@neerajprajapati3852

9 ай бұрын

@@wipergaming1448 dekho anuj yahan sin p/7 sin2p/7 sin3p/7 ki bat hai aur ye teeno non zero hain aur teen non zero quantity ka product bhi non zero hi hoga

@navisleegaming7453

Ай бұрын

Kaisa hai ​@@wipergaming1448

Need aa gyi dekhte dekhte😮

Sir please NDA ka batch start kr do yt pe please sir😢😢😢😢🙏🏼🙏🏼🙏🏼🙏🏼🙏🏼🙏🏼

You should also prove why you took the positive part

Legends ->> repload

Sir this question can be easily solved Let y = π/7 x = sin y × sin 2y × siny 3y x = (sin y × sin 2y × sin 3y × sin 4y × sin 5y × sin 6y)/ x [ because sin 4y = sin 3y , sin 5y = sin 2y and sin 6y = sin y] By using Π( multiplication of series) sin rπ/N = N /2^(N-1) x = 7/[(2^6) × x] x² = 7/2^6 x = √7 / 2³ = √7 / 8 Sir please reply to my method

π\7 ka square kyo nahi kiya

Sir isko complex no se kiya Jaye to 2 min me ho gayegaa

Assumption ka game hai...

Thank you sir

Mere se same question par cos wala ho gaya tha

Nice sir❤

If I get this question, thsn I will focus on other problems than this one. IIT JEE failed person (rank 2k in 2004) this side..lol Probably justifies why I didn't qualify for IIT but doing better than 50% IITians by knowing how the world money flows.

@sleha4106

9 ай бұрын

So how exactly does money flow

"Maths approach ka game hai " 🔥🔥

@Ayushsrivastava-nn6qg

2 ай бұрын

भाई मुझे तो पता ही नहीं था l Thanks for telling .

Inelegent Solution

Actually, this question is from a book named A das gupta

Kya sir apply formula of trigonmetric series😮

@arnavsingh7580

9 ай бұрын

Bro there is only formula for continued product of cosine series and not of Sine series

❤❤❤❤

Re-upload 😊

@30rahulukey42

9 ай бұрын

Toh last time the answer was wrong as he forgot to multiply by 8

Put value of sin 180

My whole high school life ended learning this sin-π cos-π but still i dont know where to use this math formulas in my daily life.

@SaketRaman-jh6fw

15 күн бұрын

This level of complex math is obviously not made for the average person. Its required to get into IITs and other colleges depending on the performance, the better you do, the better your placement, that's the system, there is NO application for it in your daily life.

Ye questions agar adv mein kiya toh mera IIT jayengaa....😂

❤

❤❤❤

It is from my book[arihant objective ]

apart from hard this seems to be quite a pointless problem in trigonometry, as both engineering and scientific point of view it has no significance, just few stupid formulas to learn to screw the lives of students and solve a pointless problem, how on earth would any student will logically come to the next step of getting the answer, this is mug up the solution kind of problem

Sir iat exam ke upper video bannaie 😅

@SaketRaman-jh6fw

15 күн бұрын

iat kya hota h bhai :/

Let me do it Sin 22/7 /7 will take common then(2*3) Sin22*6 Sin132 😅

Solved using complex numbers

I am read in class 6 th but I love seening this video l can understand this video 😊😊 and I am not joking😊mane apne maths wale sir se ye swal pucha tha but unohe ne 22÷7 man liya fir pura galt kar diya 😊 and i am preparing for Jee advanced and my some friend jeolus me and ma kabhi bhi 1st nhi aaya hu and i am watching this video 2024 😂 and mera result 5 aprail ko aayenga 😊❤and hare Krishna

@RajeshYadav-qc3oo

4 ай бұрын

Radhe Radhe hare Krishna ❤❤❤

@RajeshYadav-qc3oo

4 ай бұрын

Vo wahar lal nehru scool❤

@Kush11

3 ай бұрын

Lol

@MaheshKumar-lx1ku

Ай бұрын

😂😂😂😂 learn counting from 1 to 100 properly. Edit. Thanks for 2k likes.

Approach + formulae

I don't think it was too hard because your have think approach of this question by basic mind.

I learnt trigonometry in the early 70s.Now a retired banker. You said that the problem is with the approach, and not with formulae. Right? My question is why does my approach gets to be wrong. It was incorrect 50 years back and is incorrect even now.

Sir ... is it the only solution for this question..... if any solution is there please tell

@shaatirop8901

9 ай бұрын

Apply direct formula for product series

@shyamaldevdarshan

9 ай бұрын

Check my comment 😊👍

@syed3344

9 ай бұрын

​@@shaatirop8901WHAT??WHICH FORMULA