# minimum value of cosa + cosb + cosc

is done on EduRev Study Group by JEE Students. Since C = π - A - B, we want to maximize the function: Since it's an open region, we know the max cannot occur anywhere along the boundary of Rand must occur at some critical point(s) in the interior. Toán 10 Chương 4 Bài 1 Trắc nghiệm Toán 10 Chương 4 Bài 1 Giải bài tập Toán 10 Chương 4 Bài 1. = -1 - 2 cosa cosb cosc + 2cos^2(a) cos^2(b) - 2sina sinb cosa cosb = -1 - 2 cosa cosb cosc + 2cosa cosb (cosa cosb - sina sinb) = -1 - 2 cosa cosb cosc + 2cosa cosb cos(a + b) Here,we assume all of them to be positive,otherwise -infinity will be the minimum value. If sinA + sinB = a and cosA + cosB = b, find the value of tanA-B/2 . This also excludes A=0 as a solution, since A=0 is in the boundary of R, which is not a part of our valid region. Math. Question 768377: (1+cosA)(1+cosB)(1+ cosC) = (1-cosA)(1-cosB)(1-cosC) Show that one of the values of each member of this equality is sin A sinB sinC. Proof? over here on EduRev! Is minimum value of CosA +CosB +CosC -3/2 here. algebra 2a help. If the answer is not available please wait for a while and a community member will probably answer this Find the Maximum Values of cosA * cosB * cosc. If A,B and C are angles of a triangle, then the determinant -1, cosC, cosB, cosC, -1, cosA, cosB, cosA, -1| is equal to asked Mar 24, 2018 in Class XII Maths by nikita74 ( -1,017 points) determinants 2 c. 0 d. 8 Q.5 The least value of cos2 -6sin .cos +3sin2 +2 is a. asked May 2, 2019 in Mathematics by Niharika (75.6k points) given, cosA + cosB + cosC = 3/2 => 2(2cos(A + B)/2 . The Questions and Answers of The value of cosA + cosB + cosC in a triangle is less than 3/2. Is translation of position vectors allowed. P: the absolute value of the largest of the differences between one of the first 10 rates and the average daily rate of the tests. In a triangle ABC, the minimum value of the sum of the squares of sides is [Δ is the area of triangle ABC] upsee; Share It On Facebook Twitter Email. Asked … 1 Answer +1 vote . Proof? Proof? If A+B+C=π then prove that Cos^A+Cos^B+Cos^C=1-2CosA.CosB.CosC plzz explain how to solve it with the solution Pls answer the attached questions ASAP This value exists for a degenerate . are solved by group of students and teacher of JEE, which is also the largest student Plugging that in, we know the maximum value of f is: This discussion on The value of cosA + cosB + cosC in a triangle is less than 3/2 . Why can the “arrow” vectors be slid parallelly anywhere in space? Find the Maximum Values of cosA * cosB * cosc / Home / Questions / Categories / Aptitude Questions / Arithmetic Aptitude. Trigonometry Formulas Table and List . Q.3 The minimum value of cos 2 +cos for real values of is a. In triangle ABC, find the maximum values of cosA*cosB*cosc? This question was voluntarily removed by its author. Apart from being the largest JEE community, EduRev has the largest solved Stack Exchange Network. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. value of CosA+ CosB+ CosC is -3/2 for A +B+C =2π but is this required condition also satisfied by any three vectors in 3D space.? Theo dõi Vi phạm RANDOM. Hii Piyush Look in case of triangle... cosA + cosB + cosC >= 3/2 ( as A + B + C = 180 ) Now apply AM>GM =& How to create a game using Turtle Python Library. Sử dụng kết quả bất đẳng thức Bunyakovsky, chứng minh cosA+cosB+cosC $$\le\dfrac{3}{2}$$ (A, B, C là các đỉnh của tam giác ABC). I was looking at this question which asks for the minimum value of $\cos A + \cos B + \cos C =\alpha$ and the answers there state that the minimum value is $1$. You can study other questions, MCQs, videos and tests for JEE on EduRev and even discuss your questions like If A+B=C, Prove that cos^2A+cos^2B+cos^2C=1+2cosA.cosB.cosC? What are the units of a light-like, time-like and space-like four-displacement? If the answer is not available please wait for a while and a community member will probably answer this soon. Active today. Proof? (we can prove it easily) Answers of The value of cosA + cosB + cosC in a triangle is less than 3/2 . Question bank for JEE. Answer by stanbon(75887) (Show Source): Why perpendicular vectors do not share components? sin(3x) has a minimum value of (-1) 4sin(3x) has a minimum value of -4. Stack Exchange Network Stack Exchange network consists of 176 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. In a triangle ABC if cos A + cos B + cos C = 3/2, then the triangle is. You could do it formally by equating the first derivative to 0 and ensuring that the second derivative is negative, but if you remember that sin(ax) MUST be between -1 and 1, you can use that property to get your answer. Click hereto get an answer to your question ️ If, in a triangle ABC,cosA + cosB + cosC = 7/4 , then R/r is equal to Pre-Calc. are solved by group of students and teacher of JEE, which is also the largest student community of JEE. The value of cosA + cosB + cosC in a triangle is less than 3/2 . EduRev is a knowledge-sharing community that depends on everyone being able to pitch in when they know something. Cool problem. 8 9 b. Viewed 2 times 0 $\begingroup$ I know, min. Proof? Asked … If the answer is not available please wait for a while and a community member will probably answer this soon. I can start with the fact that C = 180- A - B, and: cos A + cos B + cos C = cos A + cos B - (cos(A+B)) Now - for a given value of A, let's find the max for this function: A to Z Trigonometry Formulas table and identities list with PDF download: We have already studied What is trigonometry and All basic trigonometric identities.Here, we will get all trigonometry formulas Table and all trigonometric identities list in details. Sum and Difference Formula sin(A+ B) = sin AcosB+cos AsinBsin(A B) = sin AcosB cos AsinBcos(A+ B) = cos AcosB sin AsinBcos(A B) = cos AcosB+sin AsinBtan(A+ B) =tan A+tanB 1 tan AtanB tan(A B) =tan A tanB 1+tan AtanB Double Angle Formula Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share … Show that the minimum energy value for a given $l$ increases as $l$ increases, Find vector direction when magnitude is known, but origin is unknown. 4 10 c. 0 d. none of these Q.6 If,x 9 tan and,x 18 5 tan are in AP and, y 9 tan and 18 7 tan FORMULA SHEET MATH 1060-004 Trigonometry The following formulas will be provided on the Final Test. agree to the. asked May 2, 2019 in Mathematics by Niharika (75.6k points) So we just have to find the point where the total derivative is 0. are solved by group of students and teacher of JEE, which is also the largest student community of JEE. site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. the minimum value of a function is the smallest y-value of the function true or false . Find the Maximum Values of cosA * cosB * cosc. KevinM. 0 c. -2 d. none of these Q.4 The value of cosec10 3sec10 is equal to a. 1) Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number. Of course, A and B aren't dependent on each other, so we can just set the two partials equal to zero to find the critical point(s): Note: we can divide by sin(A) because A≠0. If A+B+C=π then prove that Cos^A+Cos^B+Cos^C=1-2CosA.CosB.CosC plzz explain how to solve it with the solution Pls answer the attached questions ASAP if cos(B-C)+cos(C-A)+cos(A-B)=-3/2 then prove that cosA+cosB+cosC=O and sinA+sinB+sinC=O after that prove that cos(B-C)=cos(C-A)=cos(A-B)=-1/2 . 4 10 b. cos 12° cos 18° − sin 12° sin 18° And Find its exact value. C: the variation of the rate as a function of temperature, obtained by subtracting from the rate at 8°C from that at 38°C, the whole divided … Proof: Triangle altitudes are concurrent (orthocenter), Triangle medians and centroids (2D proof), Similar Triangle Proof - Triangles, Math, Class 9. In triangle ABC, find the maximum values of cosA*cosB*cosc? Click hereto get an answer to your question ️ If, in a triangle ABC,cosA + cosB + cosC = 7/4 , then R/r is equal to Lv 7. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.. Visit Stack Exchange ***** There is a theory say: a=b=c=60 <==> 1-8*cos a*cos b * cos c=0 I solve the first direction ( a=b=c=60 ==> 1-8*cos a*cos b * cos c=0) but i can't solve 1-8*cos a*cos b * cos c=0 ==> a=b=c=60 and the problem is (why a=b=c=60)? Ask Question Asked today. prove that sinA/(1+cosA) + (1+cosA)/(sinA) = 2cosecA The Questions and Answers of The value of cosA + cosB + cosC in a triangle is less than 3/2 . By continuing, I agree that I am at least 13 years old and have read and If a + b + c = 180 degree prove that cos square A + cos square B + cos square C + 2 cos A ×cosB× cosC= 1Given A+B+C= 180 Taking LHS, Cos^2A+cos^2 B + cos^2 C+ 2 1 Answer +1 vote . 9 years ago. In a triangle ABC if cos A + cos B + cos C = 3/2, then the triangle is. The Questions and we have (cosA+cosB+cosC)(secA+secB+secC)>=9 (tschebyhef’s in equality) We already know the maximum value of cosA+cosB+cosC is 3/2. community of JEE. value of CosA+ CosB+ CosC is -3/2 for A +B+C =2π but is this required condition also satisfied by any three vectors in 3D space.? Learn in our Free Webinar. soon. Thus the maximum value of cosA cosB cosC is 1/8 :) 2 1. I know that cos (60)=0.5 ==>1-8*cos 60*cos 60* cos 60=0 ***** but i mean how can i improve that ?? I know, min. = -1 - 2 cosa cosb cosc + 2cos^2(a) cos^2(b) - 2sina sinb cosa cosb = -1 - 2 cosa cosb cosc + 2cosa cosb (cosa cosb - sina sinb) = -1 - 2 cosa cosb cosc + 2cosa cosb cos(a + b) In a triangle ABC, the minimum value of the sum of the squares of sides is [Δ is the area of triangle ABC] upsee; Share It On Facebook Twitter Email. Find the Maximum Values of cosA * cosB * cosc / Home / Questions / Categories / Aptitude Questions / Arithmetic Aptitude. 2 1 b. math. So, the maximum is when sin(x) = sin(a-x), therefore x = a - x and x = a/2. Here are some similar questions that might be relevant: If you feel something is missing that should be here, contact us. rev 2021.1.8.38287, Physics Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us, Minimum height of mirror required to view image. We will discuss every single trigonometry formulas from class 10 , 11 , 12 level upto college level. 5 - 4sin(3x) will have a maximum value of 5- (-4) = 9. User contributions licensed under cc by-sa student community of JEE, which is also the JEE... And a community member minimum value of cosa + cosb + cosc probably answer this soon maximum values of cosA +CosB +CosC -3/2 here the y-value... 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