Question 787552
20 sin^2(x) - 21 sin(x) + 4 = 0
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*[invoke solve_quadratic_equation 20,-21,4]
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sin(x) = 0.8
x = 0.9273
x = pi - 0.9273 = 2.2134
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sin(x) = 0.25
x = 0.2527
x = pi - 0.2527 = 2.8889