In the given figure, D is the mid-point of BC, then the value of cot 𝑦 ° cot π‘₯ ° is

(a) 2   (b) 1/2  (c) 1/3  (d) 1/4

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Transcript

Question 32 In the given figure, D is the mid-point of BC, then the value of cot 𝑦 Β° cot π‘₯ Β° is (a) 2 (b) 1/2 (c) 1/3 (d) 1/4 Since D is mid-point of BC Let CD = BD = a Now, π’„π’π’•β‘γ€–π’šΒ°γ€—/𝒄𝒐𝒕⁑〖𝒙°〗 = (1/tan⁑〖𝑦°〗 )/(1/tan⁑〖π‘₯Β°γ€— ) = 1/tan⁑〖𝑦°〗 Γ—tan⁑〖π‘₯Β°γ€—/1 = 𝒕𝒂𝒏⁑〖𝒙°〗/π’•π’‚π’β‘γ€–π’šΒ°γ€— Now, tan xΒ° tan⁑〖π‘₯Β°γ€—=𝐢𝐷/𝐴𝐢 =𝒂/𝑨π‘ͺ tan yΒ° tan⁑〖𝑦°〗=𝐢𝐡/𝐴𝐢 =(π‘Ž + π‘Ž)/𝐴𝐢 =πŸπ’‚/𝑨π‘ͺ Now, π’„π’π’•β‘γ€–π’šΒ°γ€—/𝒄𝒐𝒕⁑〖𝒙°〗 = π‘‘π‘Žπ‘›β‘γ€–π‘₯Β°γ€—/π‘‘π‘Žπ‘›β‘γ€–π‘¦Β°γ€— = (π‘Ž/𝐴𝐢)/(2π‘Ž/𝐴𝐢) = π‘Ž/𝐴𝐢 Γ— 𝐴𝐢/2π‘Ž = π‘Ž/2π‘Ž = 𝟏/𝟐 So, the correct answer is (b)

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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.