SOLUTION: what is the solution set of all angles in [0,2pi) 4 cos^2x-3=0 5 sec^2x-20=0 2 cos^2 x-sin x-1=0

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Question 756390: what is the solution set of all angles in [0,2pi)
4 cos^2x-3=0

5 sec^2x-20=0

2 cos^2 x-sin x-1=0
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
what is the solution set of all angles in [0,2pi)
4 cos^2x-3=0
cos^2(x) = 3/4
cos(x) = sqrt(3)/2
x = pi/3 or x = (5/6)pi
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5 sec^2x-20=0
sec^2(x) = 4
sec(x) = +2 or -2
x = pi/6 or (11/6)pi or (5/6)pi or (7/6)pi
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2 cos^2 x-sin x-1=0
2(1-sin^2(x)) - sin(x) - 1 = 0
-2sin^2(x) - sin(x) + 1 = 0
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2sin^2(x) + sin(x) - 1 = 0
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(2sin(x)-1)(sin(x)+1) = 0
sin(x) = 1/2 or sin(x) = -1
x = pi/6 or (5/6)pi or (3/2)pi
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Cheers,
Stan H.
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