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From: "Philippe " <philippeb3@hotmail.com>
Newsgroups: comp.soft-sys.matlab
Subject: Re: how to solve trigonometric equation
Date: Wed, 8 Jun 2011 16:35:23 +0000 (UTC)
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Xref: news.mathworks.com comp.soft-sys.matlab:730869

> Sure. Just follow my instructions. I told you exactly
> what needed to be done.
>
> Let Z = sin(w*t).
>
> A*Z - B*cos(wt) + C*Z*cos(wt) + D*Z^2 - D = 0
>
> Of course, we can get the cos in terms of the sin.
>
> cos(w*t) = sqrt(1-Z^2)
>
> A bit more algebra will rid you of the square roots.
> (Hint isolate the square root term, and square.)
>
> In the end, you have a 4th degree polynomial in Z.
>
> Once you have the roots of this poly in Z, can you
> solve for t? (Yes.)
>
> Just a bit of simple algebra.
>
> John