## Trignometric equations

Trigonometric ratios and functions, the unit circle, inverse trig functions, identities, trig graphs, etc.
huriah
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Joined: Thu Mar 20, 2014 5:36 pm
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### Trignometric equations

Hi,
Solved Example:
cos^(x) + cos (x)= sin^x on 0 degree < x< 360
cos^(x) + cos (x)= 1-cos^(x)
2cos ^(x) + cos (x)-1= 0
(2cos(x) -1)(cos(x) + 1= 0
cos(x)=1/2 , cos x = -1
so complete solution is
60 degree,180 degree, 300 degree.
AS from reference angle , I know that cos 1/2 = 60 degree .But how did the book get the complete solution like 180 and 300 degree .(from where came the 180 and 300 degree)

stapel_eliz
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Joined: Mon Dec 08, 2008 4:22 pm
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cos^(x) + cos (x)= sin^x on 0 degree < x< 360
The powers (the numbers after the exponentiation symbol "^") are missing. Please reply with that information.
I know that cos 1/2 = 60 degree .But how did the book get the complete solution like 180 and 300 degree .
From the form and behavior of the cosine wave; in particular, in how the cosine wave repeats values, due to its periodic nature.