Results 1 to 5 of 5

Math Help - Coterminal Angles Work How Again?

  1. #1
    Newbie
    Joined
    Mar 2011
    Posts
    2

    Coterminal Angles Work How Again?

    Ok, so let me start by saying that this is my first post here, so I am sory if I do anything wrong, or If this is not the right place to post. If so, it is entirely un-intentional and I will do whatever I can to fix this mistake.

    I am 16, homeschooled, and teach myself. Most of you are probably wondering why I am not just asking my parents how coterminal angles work. Im not asking my parents, because I made a deal with them when I was 5 that I could homeschool as long as I didnt need their help.

    So, now that you understand why I'm here, lets get to the question.

    My understanding of coterminal angles is this:
    A coterminal angles share the same terminal line.

    By this defenition, each angle has infinite coterminal angles.

    So if this is true, why do the practice problems only have one answer?

    Thanks in advance,
    Laim.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    12
    Awards
    1
    Quote Originally Posted by Wierd View Post
    Ok, so let me start by saying that this is my first post here, so I am sory if I do anything wrong, or If this is not the right place to post. If so, it is entirely un-intentional and I will do whatever I can to fix this mistake.

    I am 16, homeschooled, and teach myself. Most of you are probably wondering why I am not just asking my parents how coterminal angles work. Im not asking my parents, because I made a deal with them when I was 5 that I could homeschool as long as I didnt need their help.

    So, now that you understand why I'm here, lets get to the question.

    My understanding of coterminal angles is this:
    A coterminal angles share the same terminal line.

    By this defenition, each angle has infinite coterminal angles.

    So if this is true, why do the practice problems only have one answer?

    Thanks in advance,
    Laim.

    Hi Wierd,

    You are right about the definition of coterminal angles. They all have the same terminal side.

    The practice problems probably (and I'm guessing here) are asking what coterminal angle between 0 and 360 degrees is equivalent to the given angle.

    For example: What coterminal angle between 0 and 360 degrees is equivalent to 450 degrees.

    Answer: 450 - 360 = 90 degrees

    Another answer would be -270 degrees if the range were to be changed to -360 < angle < 360.

    Does that help at all? The answer depends upon the range which should be given in the exercise.


    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member TheChaz's Avatar
    Joined
    Nov 2010
    From
    Northwest Arkansas
    Posts
    600
    Thanks
    2
    To rephrase/supplement masters, with the hope of furthering your understanding...

    "each angle has [an infinite number] of coterminal angles" would be a more accurate statement, and you are right in questioning how they can come up with just one answer!

    It would be like us defining "co-decimal" to mean numbers that have the same stuff after the decimal. So 4.391 and 1985.391 and -2.391 would all be co-decimal because they all have "391" after the decimal.
    If I asked for a number that is co-decimal to 4.391 but is between, say, 8 and 9, you could easily answer 8.391

    In our co-decimal example, it's easy to go between co-decimal numbers; you just add or subtract 1 (or any integer) until you're in the desired range.


    Now for coterminal angles, the process is identical; we are just adding/subtracting 360degrees (or 2π radians...) until we land in the desired range.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Mar 2011
    Posts
    2
    Thank you so much for the fast reply guys! I totaly get it now!
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Super Member TheChaz's Avatar
    Joined
    Nov 2010
    From
    Northwest Arkansas
    Posts
    600
    Thanks
    2
    You are welcome! Come back anytime.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Coterminal Angles
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: June 4th 2009, 05:08 AM
  2. trig coterminal and refrence angles
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: January 6th 2009, 08:30 PM
  3. Understanding coterminal angles
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: November 7th 2008, 09:31 AM
  4. Coterminal Angles
    Posted in the Geometry Forum
    Replies: 8
    Last Post: May 4th 2008, 01:54 PM
  5. coterminal angles
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: April 2nd 2007, 06:03 PM

Search Tags


/mathhelpforum @mathhelpforum