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Unread 18-04-2004, 19:32
Dejhan_Tulip Dejhan_Tulip is offline
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Re: Complex Equation Solver

Quote:
Originally Posted by mtrawls
Never fear, this isn't a complex equation at all! (Why, you'd have to have the sqrt of -1 for that to be the case ).

To get the answer, it is a simple trig "trick" -- i.e., once you see it it's not that hard. Think about what the inverse tangent of 12/x represents. It equals some angle from a right triangle whose "opposite" side is 12 and whose "adjacent" side is x (because tan theta is opp/adj). Then you want to find the cos (and sin) of this angle. Well, cos is adj/hyp and sin is opp/hyp -- and from the previous argument, you know both adj and opp, so all that is left is to find the hypotenouse. Just form the triangle ...

Code:
    |\
12  | \  hyp
    |_(\
     x
But from the pythagorean theorum you know that hyp = sqrt(144+x^2). Well, then you can get the system of equations in terms of x without any nasty trig functions, which should make it pretty simple to solve (I'm assuming you can solve systems of equations and the trig was throwing you off ... if not, just ask for an explanation!)

Oh, and an 89 is good for just about anything Or mathematica, if you have the software (somewhat pricey). But nothing beats pen and paper!



Thanks a lot for your reply !!

However, that is exactly what I did and the equation didn't get any simpler

If you do that and solve for X you have still cosines and sines involved and while it seems to get a little simpler it doesn't

I thought I was kind of good at doing this, I already passed all Calculus classes but this got me.

Any clarification, solution, procedure will be greatly appreciated.

Thanks a lot,

--D.T.
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