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 TalkPHP » Trigonometry...
 04-03-2010, 08:20 PM #1 (permalink) The Acquainted   Join Date: Nov 2009 Location: nr Stratford-Upon-Avon Posts: 137 Thanks: 3 Trigonometry... Ok, have been scratching my head a bit on this one... It should be simple enough as it is a right angle triangle that I am working on.. (Actually it's for stair cases) What I need to be able to find is the Hypotenuse.. Simple enough ? I thought so as well... hyp = Opposite / Sin(34) which if am understanding things right, the php should look like.. \$hyp = \$oppo / sin(35); ok, so then I realised I was getting degrees not radians.. so used.. deg2rad() \$hyp = \$oppo / deg2rad(sin(35)); and guess what, the answer I get does not match what I expect to see, I have used my daughters GCSE revision books to check the results, using :- \$hyp = 15 / deg2rad(sin(35)); \$hyp should = 26.151 (or there abouts) However I get -2007.17299864 !!!! not quite what was expecting.. HELP please.. __________________ Thanks... Simon Sex, Drugs & Linux Rules
 04-03-2010, 08:55 PM #2 (permalink) Wizard       Join Date: Sep 2007 Posts: 1,299 Thanks: 17 I hate trig unless its for calculus. When working in radians, 15/sin(35) is -35.0317748. When working in degrees it is 26.15170193. Have you ran though the math with a calculator before writing the program? __________________
 04-03-2010, 10:39 PM #3 (permalink) The Addict   Join Date: May 2009 Posts: 287 Thanks: 5 PHP's sin(\$x) expects the value to be in radians. So, you should always send it in radians. You can convert any angle in degrees to radians with this simple formula. Code: ``` value * pi / 180 pi = 3.1415926535...``` __________________ My Site
 The Following User Says Thank You to adamdecaf For This Useful Post:
 maeltar (04-04-2010)
 04-04-2010, 01:14 PM #4 (permalink) The Acquainted   Join Date: Nov 2009 Location: nr Stratford-Upon-Avon Posts: 137 Thanks: 3 Worked perfect thanks for the help :D __________________ Thanks... Simon Sex, Drugs & Linux Rules

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