OpenStax, Algebra and Trigonometry 2e §9.5 Solving Trigonometric Equations · Review Exercise 154 · Trigonometry · Identities

Solving Trigonometric Equations · Review Exercise 154

Graph each side of the equation to find the approximate solutions on the interval $[0, 2 π) .$

$20 co s^{2} x + 21 cos x + 1 = 0$

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OpenStax, Algebra and Trigonometry 2e · §9.5 Solving Trigonometric Equations · Review Exercise 154

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