Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Just need some formulas

  1. Sep 10, 2006 #1
    I haven't had precalc 2 yet, so I'm not too familiar with sin, cos, tan, but I need this for my physics class.

    So if you guys don't mind giving me the formulas of sin, cos, and tan.. for example: Sin angle A = width/length etc. If I have a right triangle with a hypotonuse of 7, and an angle of 35 degrees, what is the angle, and the other side.
     
  2. jcsd
  3. Sep 10, 2006 #2

    Math Is Hard

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    A lot of people like this little device:

    SOHCAHTOA
    Sin = Opposite/Hypotenuse SOH
    Cos = Adjacent/Hypotenuse CAH
    Tan = Opposite/Adjacent TOA
     
  4. Sep 10, 2006 #3

    Dr Transport

    User Avatar
    Science Advisor
    Gold Member

    SOHCAHTOA.......

    sin = opposite/hypotenus

    cos = adjacent/hypotenus

    tan = opposite/adjacent

    You should be able to figure it out from here....
     
  5. Sep 10, 2006 #4

    Dr Transport

    User Avatar
    Science Advisor
    Gold Member

    OK MathIsHard.... we were typing at the same time and your spelling is better than mine....
     
  6. Sep 10, 2006 #5

    Math Is Hard

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    oops, sorry, Doc! :redface:
     
  7. Sep 10, 2006 #6

    Dr Transport

    User Avatar
    Science Advisor
    Gold Member

    No problem......
     
  8. Sep 11, 2006 #7
    Well here's a question.. how do you know which is the opposite and which is the adjacent? Lets say you are given a triangle with sides of 4, 5 and 6, and you are required to find the angles.. how do you know which method to use?
     
  9. Sep 11, 2006 #8

    Kurdt

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

  10. Sep 12, 2006 #9
    I was taught that it was 'CHIEF' SOHCAHTOA !!
     
  11. Sep 12, 2006 #10

    Integral

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I was taught reading down the columns

    Oscar Sally
    Has

    A Can
    Hairy

    Old Tell
    A$$

    Trig functions work on Right triangles. H is the hypotenuse, that is the side opposite the right angle. The other 2 angles have an Adjacent side and an Opposite side. That is the opposite and Adjacent in the trig definitions.
     
  12. Aug 10, 2008 #11

    Ouabache

    User Avatar
    Science Advisor
    Homework Helper

    (i know this thread is a little dated, but still nice for reference :smile:)
    I was taught "Some Old Horse Came A Hoppin' Through Our Alley" ,
    using the first letters of each word will give you this

    sin = Some Old Horse (sin = opposite/hypotenuse)
    cos = Came A Hoppin' (cos = adjacent/hypotenuse)
    tan = Through Our Alley (tan = opposite/adjacent)
     
    Last edited by a moderator: Aug 11, 2008
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook