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Ex 3.2, 7 - Find value of cosec (-1410) - Chapter 3 Class 11

Ex 3.2, 7 - Chapter 3 Class 11 Trigonometric Functions - Part 2

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Ex 3.2, 7 Find the value of the trigonometric function cosec (–1410°) cosec (–1410°) = –cosec (1410°) = –cosec ("1410 × " 𝜋/180) = –cosec (47𝜋/6) = –cosec ("7" 5/6 𝜋) = –cosec ("8π – " 1/6 "π" ) As sin(−x) = −sin x, So, cosec(−x) = −cosec x Rough So, 47/6 = 7 5/6 = 7 + 5/6 or 8 – 1/6 We take 8 – 1/6 as it is even Values of cosec x repeats after an interval of 2π , Hence ignoring 4 × (2π) i.e. 8π = –cosec ("–" 1/6 " π" ) = –cosec ("– " 1/6 " × 180" °) = –cosec (–30°) = –(–cosec 30°) = cosec 30° = 1/sin⁡〖30°〗 = 1/(( 1/2 ) ) = 2/1 = 2 As sin(−x) = −sin x, So, cosec(−x) = −cosec x

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.