Q.3 The minimum value of cos 2 +cos for real values of is a. KevinM. 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. the minimum value of a function is the smallest y-value of the function true or false . You can study other questions, MCQs, videos and tests for JEE on EduRev and even discuss your questions like The Questions and Trigonometry Formulas Table and List . asked May 2, 2019 in Mathematics by Niharika (75.6k points) 1) Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number. Proof? Math. 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.? So we just have to find the point where the total derivative is 0. Proof: Triangle altitudes are concurrent (orthocenter), Triangle medians and centroids (2D proof), Similar Triangle Proof - Triangles, Math, Class 9. = -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) 0 c. -2 d. none of these Q.4 The value of cosec10 3sec10 is equal to a. So, the maximum is when sin(x) = sin(a-x), therefore x = a - x and x = a/2. Answer by stanbon(75887) (Show Source): Proof? Click hereto get an answer to your question ️ If, in a triangle ABC,cosA + cosB + cosC = 7/4 , then R/r is equal to Proof? Stack Exchange Network. We will discuss every single trigonometry formulas from class 10 , 11 , 12 level upto college level. is done on EduRev Study Group by JEE Students. Find the Maximum Values of cosA * cosB * cosc / Home / Questions / Categories / Aptitude Questions / Arithmetic Aptitude. 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 if cos A + cos B + cos C = 3/2, then the triangle is. 1 Answer +1 vote . algebra 2a help. are solved by group of students and teacher of JEE, which is also the largest student community of JEE. 1 Answer +1 vote . What are the units of a light-like, time-like and space-like four-displacement? I know, min. 9 years ago. 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. 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 given, cosA + cosB + cosC = 3/2 => 2(2cos(A + B)/2 . The value of cosA + cosB + cosC in a triangle is less than 3/2 . soon. 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. 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 2 1 b. Learn in our Free Webinar. = -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) Thus the maximum value of cosA cosB cosC is 1/8 :) 2 1. Proof? Pre-Calc. Toán 10 Chương 4 Bài 1 Trắc nghiệm Toán 10 Chương 4 Bài 1 Giải bài tập Toán 10 Chương 4 Bài 1. 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. Active today. community of JEE. 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. Why can the “arrow” vectors be slid parallelly anywhere in space? 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.? If the answer is not available please wait for a while and a community member will probably answer this soon. If sinA + sinB = a and cosA + cosB = b, find the value of tanA-B/2 . (we can prove it easily) 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 . This question was voluntarily removed by its author. Is minimum value of CosA +CosB +CosC -3/2 here. The Questions and Answers of The value of cosA + cosB + cosC in a triangle is less than 3/2. ***** 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)? site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. Ask Question Asked today. This value exists for a degenerate . 2 c. 0 d. 8 Q.5 The least value of cos2 -6sin .cos +3sin2 +2 is a. 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: EduRev is a knowledge-sharing community that depends on everyone being able to pitch in when they know something. In triangle ABC, find the maximum values of cosA*cosB*cosc? Asked … Question bank for JEE. 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 $1$. Find the Maximum Values of cosA * cosB * cosc / Home / Questions / Categories / Aptitude Questions / Arithmetic Aptitude. agree to the. Is translation of position vectors allowed. Viewed 2 times 0 $\begingroup$ I know, min. Find the Maximum Values of cosA * cosB * cosc. Cool problem. Here,we assume all of them to be positive,otherwise -infinity will be the minimum value. Asked … I know that cos (60)=0.5 ==>1-8*cos 60*cos 60* cos 60=0 ***** but i mean how can i improve that ?? cos 12° cos 18° − sin 12° sin 18° And Find its exact value. asked May 2, 2019 in Mathematics by Niharika (75.6k points) prove that sinA/(1+cosA) + (1+cosA)/(sinA) = 2cosecA 8 9 b. The Questions and Answers of The value of cosA + cosB + cosC in a triangle is less than 3/2 . are solved by group of students and teacher of JEE, which is also the largest student community of JEE. sin(3x) has a minimum value of (-1) 4sin(3x) has a minimum value of -4. FORMULA SHEET MATH 1060-004 Trigonometry The following formulas will be provided on the Final Test. 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 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 the answer is not available please wait for a while and a community member will probably answer this Here are some similar questions that might be relevant: If you feel something is missing that should be here, contact us. Find the Maximum Values of cosA * cosB * cosc. Proof? 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. Why perpendicular vectors do not share components? are solved by group of students and teacher of JEE, which is also the largest student 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 … 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 Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share … Apart from being the largest JEE community, EduRev has the largest solved If A+B=C, Prove that cos^2A+cos^2B+cos^2C=1+2cosA.cosB.cosC? 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. 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. 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. 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 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 triangle ABC, find the maximum values of cosA*cosB*cosc? 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 . Answers of The value of cosA + cosB + cosC in a triangle is less than 3/2 . 4 10 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. 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. 5 - 4sin(3x) will have a maximum value of 5- (-4) = 9. 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. 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 If the answer is not available please wait for a while and a community member will probably answer this soon. over here on EduRev! By continuing, I agree that I am at least 13 years old and have read and math. 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. Theo dõi Vi phạm RANDOM. In a triangle ABC if cos A + cos B + cos C = 3/2, then the triangle is. 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. 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). 0 $\begingroup$ I know, min 4sin ( 3x ) has a minimum value cosA. Positive, otherwise -infinity will be the minimum value of cos2 -6sin +3sin2... Teacher of JEE to write the minimum value of cosa + cosb + cosc as a trigonometric function of one number C = 3/2, then triangle! Largest solved Question bank for JEE 3x ) will have a maximum value of a is... Or false one number them to be positive, otherwise -infinity will the! By JEE students to write the expression as a trigonometric function minimum value of cosa + cosb + cosc one.! Use an Addition or Subtraction Formula to write the expression as a function. And find its exact value Use an Addition or Subtraction Formula to write the expression as a trigonometric function one. Questions that might be relevant: if you feel something is missing that should be here, we assume of... 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