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Title: How should this trigonometric equation be solved? Math professors? Post by: Firas on Oct 29, 2012 I was able to do it, but it took up a whole sheet of paper, front and back. Is there a quick(er) way to this? Very interested to know...please post how you did it. 10 POINTS WILL BE AWARDED.
Find the exact solutions of the equation in the interval [0, 2?). tan 2x - 2 cos x = 0 Looks harmless, I know, but it's pure evil I tell you. Title: How should this trigonometric equation be solved? Math professors? Post by: nwobie on Oct 29, 2012 Content hidden
Title: How should this trigonometric equation be solved? Math professors? Post by: jujubee on Oct 29, 2012 tan 2x = 2 cos x
2 cos x = 2 sin 2x/cos 2x = 2 sin x cos x /(1 - 2 sin^2 x) 1 - 2 sin ^2 x = sin x, plus you have to check the cases sin^2 x = 1/2 or cos = 0. The main case is a simple quadratic equation in sin x that can be solved by the FOIL method. |