If the angles of βˆ†ABC are in ratio 1 : 1 : 2, respectively (the largest angle being angle C), then the value of  (sec A)/(cosec B)-tan⁡A/cot⁡B  is :

(a) 0   (b) 1/2  (c) 1   (d) √3  /2

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Transcript

Question 14 If the angles of βˆ†ABC are in ratio 1 : 1 : 2, respectively (the largest angle being angle C), then the value of (𝑠𝑒𝑐 𝐴)/(π‘π‘œπ‘ π‘’π‘ 𝐡)βˆ’tan⁑𝐴/cot⁑𝐡 is : (a) 0 (b) 1/2 (c) 1 (d) √3 /2 Since angles are in ratio 1 : 1 : 2 Let angles be ∠ A = x ∠ B = x ∠ C = 2x Now, In Ξ” ABC By Angle sum property ∠ A + ∠ B + ∠ C = 180Β° x + x + 2x = 180Β° 4x = 180Β° x = (180Β° )/4 x = 45Β° Thus, ∠ A = x = 45Β°, ∠ B = x = 45Β° , ∠ C = x = 90Β° Now, (𝑠𝑒𝑐 𝐴)/(π‘π‘œπ‘ π‘’π‘ 𝐡)βˆ’tan⁑𝐴/cot⁑𝐡 = (𝒔𝒆𝒄 πŸ’πŸ“Β° )/(𝒄𝒐𝒔𝒆𝒄 πŸ’πŸ“Β°)βˆ’π’•π’‚π’β‘γ€–πŸ’πŸ“Β°γ€—/π’„π’π’•β‘γ€–πŸ’πŸ“Β° γ€— = √2/√2βˆ’1/1 = 1 βˆ’ 1 = 0 So, the correct answer is (a)

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.