Find the exact values of the following trigonometric ratios

MATHEMATICS · Multi-part · A Level · Mathematics · Trigonometry · Trigonometry

Problem

Find the exact values of the following trigonometric ratios. Show each reduction step that brings the given angle into the interval 0≤x<2π0\le x<2\pi and state the final value obtained from the unit circle. (i) sin⁡(13π6)\sin \left( \dfrac{13\pi}{6} \right) (ii) cos⁡(−7π4)\cos \left( -\dfrac{7\pi}{4} \right) (iii) tan⁡(19π3)\tan \left( \dfrac{19\pi}{3} \right) (iv) csc⁡(−11π6)\csc \left( -\dfrac{11\pi}{6} \right) (v) sec⁡(17π4)\sec \left( \dfrac{17\pi}{4} \right)

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