SOLUTION: Find all solutions in [0, 2pi] to three decimal places. 3cos^2(x)+5cosx=2

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Question 535029: Find all solutions in [0, 2pi] to three decimal places. 3cos^2(x)+5cosx=2
Answer by lwsshak3(11628) About Me  (Show Source):
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Find all solutions in [0, 2pi] to three decimal places. 3cos^2(x)+5cosx=2
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3cos^2(x)+5cosx=2
3cos^2(x)+5cosx-2=0
(3cosx-1)(cosx+2)=0
..
cosx+2=0
cosx=-2 (reject, -1 ..
3cosx-1=0
cosx=1/3
arccosx(1/3)=1.231 and 5.052 radians (in quadrants I and IV)