SOLUTION: Solving the following equation will require you to use the quadratic formula. Solve the equation for θ between 0° and 360°, and round your answers to the nearest tenth of a de

Algebra ->  Trigonometry-basics -> SOLUTION: Solving the following equation will require you to use the quadratic formula. Solve the equation for θ between 0° and 360°, and round your answers to the nearest tenth of a de      Log On


   

Question 960693: Solving the following equation will require you to use the quadratic formula. Solve the equation for θ between 0° and 360°, and round your answers to the nearest tenth of a degree. (Enter your answers as a comma-separated list.)
4 cos2 θ + 5 sin θ − 1 = 0
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Solve the equation for θ between 0° and 360°, and round your answers to the nearest tenth of a degree. (Enter your answers as a comma-separated list.)
4 cos^2(θ) + 5 sin(θ) − 1 = 0
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cos(t) = [-5 +- sqrt(25-4*4*-1)]/8
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cos(t) = [-5 +- sqrt(41)]/8
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cos(t) = [-5+sqrt(41)]/8 or cos(t) = [-5-sqrt(41)]/8
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cos(t) = 0.1754 or cos(t) = -1.4254 (extraneous)
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t = arccos(0.1754) = 79.9 degrees or 439.9 degrees
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Cheers,
Stan H.
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