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You are not logged in. #1 20050904 09:48:11
the formulas for sine, cosine and tangentI would like to right some simple C++ programs to do some vector calculations and stuff but I need a way to calculate sine, cosine and tangent. I take it most computers have the formula's built in somewhere but I think it might be educational (mathematicly) and good programming practice to write my own algorithm. I've seen a few differant formulas for more or less accurate calculations on the internet but the explanations are often quite confusing. Using words to express yourself is not what mathematicians do best. A logarithm is just a misspelled algorithm. #2 20050905 16:14:13
Re: the formulas for sine, cosine and tangentThis may help. El que pega primero pega dos veces. #5 20050906 05:35:47
Re: the formulas for sine, cosine and tangent"^" means to raise to a power. It's necessary on plain text documents that don't support superscripts. It's also an operator in many programming languages, including, I think, C/++, so you can use it in your programs to raise things to a power. El que pega primero pega dos veces. #6 20050906 07:52:15
Re: the formulas for sine, cosine and tangentI wrote this in Just BASIC v1.0. Code:'Note: dangle is angle in degrees and rangle is angle in radians for dangle = 0 to 90 step 5 pi = 3.141592653589793238462643383279502884197169399375105820974944 rangle=(pi*dangle)/180 'Note: cos(x) = 1  x^2/2! + x^4/4!  x^6/6! + ... rangleSqrd=rangle * rangle diver = 0 nextTerm = 1 cosineNow = 1 for iter=1 to 10 for d1 = 1 to 2 diver = diver + 1 nextTerm = nextTerm / diver next d1 nextTerm = 0  nextTerm nextTerm = nextTerm * rangleSqrd cosineNow = cosineNow + nextTerm next iter print "Cosine( ";dangle;" ) = ";cosineNow next dangle igloo myrtilles fourmis #7 20050906 08:39:47
Re: the formulas for sine, cosine and tangentCode looks right to me. Does it work in all quadrants (90° to 360°) ? "The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  Leon M. Lederman #8 20050906 09:07:21
Re: the formulas for sine, cosine and tangentIt works in all four quadrants, but the floating point math isn't that precise in this language I used Last edited by John E. Franklin (20050906 09:08:39) igloo myrtilles fourmis #9 20050906 22:37:08
Re: the formulas for sine, cosine and tangentMight be a good idea to first automaticly reduce the arguement. I don't know this languagel but, as the first step of the function, in C++ you could just say A logarithm is just a misspelled algorithm. #10 20050907 07:17:57
Re: the formulas for sine, cosine and tangentThe following web page says you can use any value of x in the cosine summation and the sine too. Last edited by John E. Franklin (20050908 00:53:55) igloo myrtilles fourmis #12 20050907 22:34:42
Re: the formulas for sine, cosine and tangent
Or ... "The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  Leon M. Lederman #13 20050908 00:49:38
Re: the formulas for sine, cosine and tangentThose are two very nice calculators! I'm impressed. I started writing my large digit calculation program yesterday, so I'll continue with that. Plus, I'm not very good at examining programs written by others, and I like writing things from scratch. igloo myrtilles fourmis 