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Word problem,Trig functions

  1. Jul 21, 2011 #1
    1. The problem statement, all variables and given/known data
    13) An angle has a radian measure of Pi/8 . Find the exact radian measure of

    a) Its supplement
    b) Its complement

    2. Relevant equations

    3. The attempt at a solution

    I tried converting it to degrees by doing degrees / pi and then doing 90 - that angle i got to give me supplement / compliment, then re convert it back into radiants, However that didnt work.

    Does anyone know how to solve this?
  2. jcsd
  3. Jul 21, 2011 #2


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    Homework Helper

    You don't need to convert to degrees; however, if you really want to, you want to multiply by 180/π. I don't know what you mean by "degrees/pi".

    "90 - that angle"... does that give you the supplement, the complement, or both? You're not making any sense here.

    Instead of converting π/8 to degrees, convert 90° to radians (and it's 90°, not 90 - if there's no degree mark, radians is assumed) and then perform the subtraction.
  4. Jul 22, 2011 #3
    An important part of trig is learning to think in radians, so converting to degrees isn't suggested.

    My tenth grade geometry teacher told us that 'c' is for corner, and 's' is for straight. So the complement is what you add to your angle to get a right angle; and the supplement is what you add to get a straight angle.

    How many radians are in a right angle? How many in a straight angle?
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