# Trigo + Binomial!

Probability Level 4

$1+\dfrac{1}{3}+\dfrac{1}{3}\cdot\dfrac{3}{6}+\dfrac{1}{3}\cdot\dfrac{3}{6}\cdot\dfrac{5}{9}+\dfrac{1}{3}\cdot\dfrac{3}{6}\cdot\dfrac{5}{9}\cdot\dfrac{7}{12}+\cdots=2\cos\theta$

Find the value of $\theta$ in degrees if $0 \le \theta \le π$ .

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