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trig identities in java

  • 23-12-2014 12:23AM
    #1
    paulbok
    Registered Users, Registered Users 2 Posts: 5,229 ✭✭✭


    I'm trying to use a formula that has sin^2(x/2) (sin squared x, not sin x squared) in it, but Math.sin^2 doesn't exist in the Math method.

    Does anyone know how to express it in java?

    I've found examples that give sin(x/2) or has sin(x/2)*sin(x/2)
    but they don't give the correct result.

    I've found one alternative, sin^2 = 1/2 - 1/2cos(2x) but that doesn't work for me either.

    it's the Haversine formula for working out distance along the earths surface from to lat/long points.


Comments

  • #2
    GreeBo
    Registered Users, Registered Users 2 Posts: 27,517 ✭✭✭✭GreeBo


    Sin squared x is equal to sin x * sin x

    It's written that way to about confusion with sin ( x*x)


  • #3
    paulbok
    Registered Users, Registered Users 2 Posts: 5,229 ✭✭✭paulbok


    Right so, back to the drawing board then.


  • #4
    GreeBo
    Registered Users, Registered Users 2 Posts: 27,517 ✭✭✭✭GreeBo


    You could also Google and get several java implementations...


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