Ex 8.1, 2 - Chapter 8 Class 10 Introduction to Trignometry

Last updated at April 16, 2024 by

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Ex 8.1, 2 In figure , find tan P – cot R. Finding sides of triangle In right βˆ† 𝑷𝑸𝑹, Using Pythagoras theorem (Hypotenuse)2 = (Height)2 + (Base)2 PR2 = PQ2 + QR2 132 = 122 + QR2 169 = 144 + QR2 169 – 144 = QR2 25 = QR2 QR2 = 25 QR = βˆšπŸπŸ“ QR = √(5^2 ) QR = 5 Thus, QR = 5 cm Finding tan P tan P = (𝑠𝑖𝑑𝑒 π‘œπ‘π‘π‘œπ‘ π‘–π‘‘π‘’ π‘‘π‘œ βˆ π‘ƒ)/(𝑠𝑖𝑑𝑒 π‘Žπ‘‘π‘—π‘Žπ‘π‘’π‘›π‘‘ π‘‘π‘œβˆ π‘ƒ) = 𝑄𝑅/𝑃𝑄 = πŸ“/𝟏𝟐 Finding cot R For cot R , Lets first find tan R tan R = (𝑠𝑖𝑑𝑒 π‘œπ‘π‘π‘œπ‘ π‘–π‘‘π‘’ π‘‘π‘œ βˆ π‘…)/(𝑠𝑖𝑑𝑒 π‘Žπ‘‘π‘—π‘Žπ‘π‘’π‘›π‘‘ π‘‘π‘œβˆ π‘…) = 𝑃𝑄/𝑄𝑅 = 𝟏𝟐/πŸ“ Hence, cot R = 1/tan⁑〖 𝑅〗 = πŸ“/𝟏𝟐 Now, tan P – cot R = 5/12βˆ’5/12 = 0

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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.