Write An Equation

Discussion in 'Geometry and Trigonometry' started by nycmathguy, Jan 15, 2022.

  1. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    Section 6.1

    I need help setting up the needed equation.
    I would like this problem to be done in step by step fashion. I want to learn how to put together the equation required using the information in the photo. This question ends Section 6.1 for us. Next section, Law of Cosines.

    Screenshot_20220109-195950_Samsung Notes.jpg
     
    nycmathguy, Jan 15, 2022
    #1
  2. nycmathguy

    MathLover1

    Joined:
    Jun 27, 2021
    Messages:
    2,989
    Likes Received:
    2,884
    the angle B=180- ϕ
    d/sin(θ )=2/sin(180- ϕ)
    solve for d
     
    MathLover1, Jan 15, 2022
    #2
    nycmathguy likes this.
  3. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    d/sin(θ )=2/sin(180- ϕ)

    Solve for d.

    2sin(θ )= d[2/sin(180- ϕ)]

    2sin(θ )/[2/sin(180- ϕ)] = d

    Yes?
     
    nycmathguy, Jan 16, 2022
    #3
  4. nycmathguy

    MathLover1

    Joined:
    Jun 27, 2021
    Messages:
    2,989
    Likes Received:
    2,884
    d/sin(θ )=2/sin(180- ϕ)........both sides multiply by sin(θ )

    dsin(θ )/sin(θ )=2sin(θ )/sin(180- ϕ).......simplify

    d=2sin(θ )/sin(180- ϕ)
     
    MathLover1, Jan 16, 2022
    #4
    nycmathguy likes this.
  5. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    Are you saying that I forgot to further simplify? Did I solve for d incorrectly?
     
    nycmathguy, Jan 16, 2022
    #5
  6. nycmathguy

    MathLover1

    Joined:
    Jun 27, 2021
    Messages:
    2,989
    Likes Received:
    2,884
    yes, you made mistake
    your solution is 2sin(θ )/[2/sin(180- ϕ)] = d which is [​IMG] , when you simplify that you get [​IMG] which is incorrect

    correct answer is [​IMG]
     
    MathLover1, Jan 16, 2022
    #6
    nycmathguy likes this.
  7. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    Beautiful. What does the answer look like on the xy-plane?
     
    nycmathguy, Jan 17, 2022
    #7
  8. nycmathguy

    MathLover1

    Joined:
    Jun 27, 2021
    Messages:
    2,989
    Likes Received:
    2,884
    in the xy-plane, d represents y, sin function represents x
     
    MathLover1, Jan 17, 2022
    #8
    nycmathguy likes this.
  9. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    Ok. I will try graphing it on paper when time allows.
     
    nycmathguy, Jan 17, 2022
    #9
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.