Proof? Proof? The Questions and 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). Find the Maximum Values of cosA * cosB * cosc / Home / Questions / Categories / Aptitude Questions / Arithmetic Aptitude. 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 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. 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. are solved by group of students and teacher of JEE, which is also the largest student community of JEE. If the answer is not available please wait for a while and a community member will probably answer this soon. sin(3x) has a minimum value of (-1) 4sin(3x) has a minimum value of -4. 9 years ago. Ask Question Asked today. ***** 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)? 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. 0 c. -2 d. none of these Q.4 The value of cosec10 3sec10 is equal to a. Thus the maximum value of cosA cosB cosC is 1/8 :) 2 1. Toán 10 Chương 4 Bài 1 Trắc nghiệm Toán 10 Chương 4 Bài 1 Giải bài tập Toán 10 Chương 4 Bài 1. The Questions and Answers of The value of cosA + cosB + cosC in a triangle is less than 3/2 . 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. is done on EduRev Study Group by JEE Students. asked May 2, 2019 in Mathematics by Niharika (75.6k points) Click hereto get an answer to your question ️ If, in a triangle ABC,cosA + cosB + cosC = 7/4 , then R/r is equal to 8 9 b. Here are some similar questions that might be relevant: If you feel something is missing that should be here, contact us. are solved by group of students and teacher of JEE, which is also the largest student community of JEE. If A+B=C, Prove that cos^2A+cos^2B+cos^2C=1+2cosA.cosB.cosC? asked May 2, 2019 in Mathematics by Niharika (75.6k points) algebra 2a help. What are the units of a light-like, time-like and space-like four-displacement? Answer by stanbon(75887) (Show Source): 2 1 b. Math. 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 . This value exists for a degenerate . Click hereto get an answer to your question ️ If, in a triangle ABC,cosA + cosB + cosC = 7/4 , then R/r is equal to If sinA + sinB = a and cosA + cosB = b, find the value of tanA-B/2 . In triangle ABC, find the maximum values of cosA*cosB*cosc? 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. 1) Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number. 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. 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 $1$. Asked … Find the Maximum Values of cosA * cosB * cosc. site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. 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. Q.3 The minimum value of cos 2 +cos for real values of is a. Is translation of position vectors allowed. given, cosA + cosB + cosC = 3/2 => 2(2cos(A + B)/2 . So we just have to find the point where the total derivative is 0. 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 agree to the. 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 soon. I know that cos (60)=0.5 ==>1-8*cos 60*cos 60* cos 60=0 ***** but i mean how can i improve that ?? The value of cosA + cosB + cosC in a triangle is less than 3/2 . FORMULA SHEET MATH 1060-004 Trigonometry The following formulas will be provided on the Final Test. 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. 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 . 4 10 b. I know, min. Asked … 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 Trigonometry Formulas Table and List . are solved by group of students and teacher of JEE, which is also the largest student 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. over here on EduRev! 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 Answers of The value of cosA + cosB + cosC in a triangle is less than 3/2 . 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