Given that A+B =120¢ª and CosA + Cos B = 1/¡î2 show that cos(A+B)/2 =1/¡î2

  1. 👍 0
  2. 👎 0
  3. 👁 202

Respond to this Question

First Name

Your Response

Similar Questions

  1. 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

    asked by Binoy kumar mahato on October 6, 2017
  2. Trigonometry

    Prove that 1-cosA+cosB-cos(A+B)/1+cosA-cosB-cos(A+B) = tanA/2cotA/2

    asked by Kewal on January 4, 2012
  3. Trigonometry

    Prove that cos(A+B)cosC - cos(B+C)cosA = sinBsin(C-A)

    asked by Kewal on December 30, 2011
  4. maths (trigonometry)

    please solve these if possible Q1. If sinx +siny=3(cosy-cosx) then the value of sin3x/sin3y. Q2. If sina ,cosa,and tan a are in g.p.then cos cubea+cos square a is equal to

    asked by marley on June 6, 2011
  5. Pre-Cal (Trig) Help?

    The following relationship is known to be true for two angles A and B: cos(A)cos(B)-sin(A)sin(B)=0.957269 Express A in terms of the angle B. Work in degrees and report numeric values accurate to 2 decimal places. So I'm pretty

    asked by Giovanni on May 6, 2016
  1. MathsSs triG

    Consider sin(x-360)sin(90-x)tan(-x)/cos(90+x) 1.A.SIMPLIFY sin(x-360)sin(90-x)tan(-x)/cos(90+x) to a single trigonometric ratio B.hence or otherwise without using a calculator,solve for X if 0

    asked by katlego ratsoma on October 3, 2013
  2. Math

    Explain how to do this with steps please. 1. Simplify cos(x-y)+cos(x+y)/cosx I did some of these so far, don't know if it is correct. Formula: cosxcosy= cos(x+y)+cos(x-y)/2 cos(x-y)+cos(x+y)/cosx =cosxcosy/2cosx

    asked by Jake on January 26, 2012
  3. Please help me with Trig

    Given cos 67.5° = [√(2+√2)]/2, find tan 67.5° , simplify where needed, and show work. I'm starting to learn this stuff, and I'm so confused where to start. I know they gave me the coordinate X as in cos 67.5° =

    asked by Jane on January 27, 2016
  4. Studying for Pre Cal exam

    Find the fourth roots of − 1/2 + (square root)3/2 i Write the roots in trigonometric form. A - w 1=cos(35°)+isin(35°) w2 =cos(125°)+isin(125°) w3 =cos(215°)+isin(215°) w4 =cos(305°)+isin(305°) B - w1

    asked by Lottie on July 13, 2016
  5. trig

    Reduce the following to the sine or cosine of one angle: (i) sin145*cos75 - cos145*sin75 (ii) cos35*cos15 - sin35*sin15 Use the formulae: sin(a+b)= sin(a) cos(b) + cos(a)sin(b) and cos(a+b)= cos(a)cos(b) - sin(a)sin)(b) (1)The

    asked by Paul C on November 26, 2006
  6. Algebra

    Write an equation for the translation of the function. y = cos x; translated 6 units up A. y = cos x- ­ 6 B. y = cos(x + 6) C. y = cos x + 6 D. y = cos(x ­ 6) I think its B or c..

    asked by Veronika on February 23, 2016

You can view more similar questions or ask a new question.