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Homework Help: How do I calculate inverse trig functions?

  1. Mar 24, 2016 #1
    • Member warned about posting without using the homework template
    On the paper I'm reading the arctan of 35 over 65 is approx. 28.30degrees.

    When I use the Google calculator "arctan(35/65)" gives me 0.493941369 rad.

    What am I doing wrong?
  2. jcsd
  3. Mar 24, 2016 #2


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    What is 28.30 degrees in radians?
  4. Mar 24, 2016 #3
    Ah, I wasn't told I could convert radians to degrees. Thank you. :eek:
  5. Mar 24, 2016 #4

    Ray Vickson

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    Nobody has to ""allow"" you to change units; you can do it if you want to, and sometimes you MUST do it (as in this case).
  6. Mar 24, 2016 #5


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    That's what the 'RAD'/'DEG' button in the upper left hand calculator is for, to allow you to select the units of angular measure.

    Haven't you ever used a regular calculator with this feature?
  7. Mar 24, 2016 #6
    No, I did poorly in my Math exams. Now I am going to be studying science and engineering which is very ambitious if you think about my past with mathematics. But now I'm 18 it isn't very difficult to grasp different concepts so I'm learning at a much faster rate. My only problem is not being distracted. Thanks for notifying me of the option on the calculator, I never noticed it before.
  8. Mar 28, 2016 #7
    Hey, one radian is 180 degrees / pi, which is about 57.3 degrees.

    In other words, 360 degrees is equal to 2*pi radians. Keep these numbers in mind, they may save you in future tests / quizzes!
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