Question 1036368
Solve the following questions for 0. Unless otherwise specified, give all solutions as exact radian measures 
20cos^2 0-5 cos 0 + 10 = 13
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Sub x for the cosine
20x^2 - 5x - 3 = 0
*[invoke solve_quadratic_equation 20,-5,-3]
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cos = as stated above
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Use a calculator to find the principal values.
No exact solution is possible.