Half-Angle Formulas...3

Discussion in 'Geometry and Trigonometry' started by nycmathguy, Jan 1, 2022.

  1. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    Section 5.5

    Screenshot_20211231-174444_Samsung Notes.jpg

    IMG_20211231_195927.jpg

    IMG_20211231_195940.jpg

    IMG_20211231_195954.jpg
     
    nycmathguy, Jan 1, 2022
    #1
  2. nycmathguy

    MathLover1

    Joined:
    Jun 27, 2021
    Messages:
    2,989
    Likes Received:
    2,884
    answer is -2 - sqrt(3)

    tan(7pi/12)=sin(7pi/6)/(1+cos(7pi/6))
    tan(7pi/12)=(-1/2)/(1-sqrt(3)/2)
    tan(7pi/12)=-1/(2(1-sqrt(3)/2)
    tan(7pi/12)=-1/(2-sqrt(3))......rationalize
    tan(7pi/12)=-(2+sqrt(3))/(((2-sqrt(3))(2+sqrt(3)))
    tan(7pi/12)=-(2+sqrt(3))/(1)
    tan(7pi/12)=-(2+sqrt(3))
    tan(7pi/12)=-2-sqrt(3)
     
    MathLover1, Jan 1, 2022
    #2
    nycmathguy likes this.
  3. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    Another sign error. Cool. Take away a few points.
     
    nycmathguy, Jan 1, 2022
    #3
    MathLover1 likes this.
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Similar Threads

  1. Half-Angle Formulas...1

  2. Half-Angle Formulas...2

Loading...