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Express the following in term of angles between 0° and 45° : cosec 68° + cot 72° - Mathematics

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Question

Express the following in term of angles between 0° and 45° :

cosec 68° + cot 72°

Sum
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Solution

cosec 68° + cot 72°

= cosec(90° – 22°) + cot(90° – 18°)  ...(∵ cosec(90° – θ) = sec θ and cot(90° – θ) = tan θ)

= sec 22° + tan 18°

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Chapter 25: Complementary Angles - Exercise 25 [Page 310]

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Selina Concise Mathematics [English] Class 9 ICSE
Chapter 25 Complementary Angles
Exercise 25 | Q 4.2 | Page 310

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