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What do the Trigonometic functions mean?

  1. Jan 16, 2013 #1
    I know what the Trigonometric functions are but I dont know what they mean.
    For example sinθ=opp/hyp, but It just seems like Im plugging in the sides to get random numbers. I JUST started learning Trigonometry, Im not that advanced in math, so can you please explain it in such a way someone who knows diddly squat about this stuff can understand?

  2. jcsd
  3. Jan 16, 2013 #2


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    You basically already gave the answer in that single formula: sinθ=opp/hyp.

    What they do is relate the angles in triangles to the length of the sides. And actually, it's not the length of one side, but a ratio of two lengths. Often, the sides of the triangles by themselves don't mean a whole lot. A lot of triangles are just rescaled versions of the same basic one. In this case, looking at the ratio of the sides gets rid of that unnecessary distinction.

    In fact, if I tell you the three angles of a triangle (say, 30, 65 and 85 degrees) you will be able to exactly draw the triangle I have in mind, except for how big it is (unless I tell you the length of one of the sides).

    Why is relating sides and angles so important? Well, just ask anyone who has ever used a sextant to convert angles into distances. Or a modern day road worker, who also uses that information to decide whether he's built a flat road. Or a builder, geologist, physicist, anyone placing a ladder against a building, etc.

    For an impression of the number of trig functions around, see Wikipedia: 300px-Circle-trig6.svg.png

    You can see that for basically any relevant measure relating to a straight line and a circle, a trig function is available.
  4. Jan 16, 2013 #3
    OH MY GOD THANKYOU! You saved me!
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