Basic Trig Question

This is a discussion on Basic Trig Question within the Tech Board forums, part of the Community Boards category; CAS is good for checking for mistakes/errors. So, two angles and, knowing the area, perhaps the Hedron formula (which, I ...

  1. #16
    C++まいる!Cをこわせ! Elysia's Avatar
    Join Date
    Oct 2007
    Posts
    22,173
    CAS is good for checking for mistakes/errors.
    So, two angles and, knowing the area, perhaps the Hedron formula (which, I never really knew existed)?
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.
    For information on how to enable C++11 on your compiler, look here.
    よく聞くがいい!私は天才だからね! ^_^

  2. #17
    Registered User
    Join Date
    Dec 2006
    Location
    Canada
    Posts
    3,145
    To solve for a triangle, you need 3 independent pieces of information -

    3 sides, 2 sides + 1 angle, 1 side + 2 angles, but not 3 angles, because the third one becomes redundant.

    2 sides + area also works because Heron's formula gives you the third side.

    I'm not sure if 2 angles + area works. By this logic it should, but I can't think of how.

  3. #18
    Password:
    Join Date
    Dec 2009
    Location
    NC
    Posts
    587
    Infinitely many triangles with the same angles and area? I don't think so. Give me an example of 2 triangles with the same internal angles and area, but different sides. You can't.

    Law of Cos gives you a third side. Heron's(which I just remembered isn't what I was using) depends on the length of the sides. The formula I used has no name, I got it out of my precal book. It works, there no reason debating it until you give an example where it doesn't.

    >> I'm not sure if 2 angles + area works
    Given 2 angles, you can always derive the 3rd. Just subtract the 2 from 180... From 3 angles and area, just use my formulas.

    >> To solve for a triangle, you need 3 independent pieces of information -
    3 angles, and area. area being dependent on angles and side length.
    Last edited by User Name:; 11-14-2010 at 05:33 PM.

  4. #19
    Registered User
    Join Date
    Dec 2006
    Location
    Canada
    Posts
    3,145
    That's why I said it should be possible to solve for the triangle, but I don't know how.

  5. #20
    Password:
    Join Date
    Dec 2009
    Location
    NC
    Posts
    587
    I just showed you how!

    Code:
    a = sqrt((2*sinA*K)/(sinB*sinC))
    b = sqrt((2*sinB*K)/(sinA*sinC))
    c = sqrt((2*sinC*K)/(sinA*sinB))
    Lowercase being sides and uppercase being their opposite angles.

  6. #21
    Registered User
    Join Date
    Dec 2006
    Location
    Canada
    Posts
    3,145
    Ah! ok. I'll admit I only skimmed the thread .

Page 2 of 2 FirstFirst 12
Popular pages Recent additions subscribe to a feed

Similar Threads

  1. A basic math programming question
    By hebali in forum C Programming
    Replies: 38
    Last Post: 02-25-2008, 03:18 PM
  2. Basic question about GSL ODE func RK4
    By cosmich in forum Game Programming
    Replies: 1
    Last Post: 05-07-2007, 02:27 AM
  3. Basic question about RK4
    By cosmich in forum C++ Programming
    Replies: 0
    Last Post: 05-07-2007, 02:24 AM
  4. Basic C question ---- URGENT
    By x135 in forum Linux Programming
    Replies: 3
    Last Post: 03-25-2006, 10:05 PM
  5. A very basic question
    By AshFooYoung in forum C Programming
    Replies: 8
    Last Post: 10-07-2001, 03:37 PM

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21