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Find all solutions of given equation
2cosx-1=0


Sagot :

AL2006
There are an infinite number of solutions, so I don't plan to list them all.
I'll list two of them, and then describe how to get all of the rest.

You said that      2cos(x) - 1  =  0

Add  1  to each side:     2cos(x) = 1

Divide each side by  2:    cos(x) = 1/2

The angles whose cosine is 1/2 are  60 degrees, 300 degrees,
and any multiple of 360 degrees added to either of those.
2cosx=1
cosx=1/2
x=cos∧-1(1/2)
x=60degrees or 360-60=300degrees
depending on your limits if in radians pi/3 and 5pi/3