Тангенс косинус. Помогите

Question

Тангенс косинус. Помогите

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Answer 1

Tan(π/6) = 1/√3
tan(π/3) = √3
cos(π/6) = √3/2

( 2 * (1/√3) - √3) * √3/2 = -1/√3 * √3/2 = -2