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Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class


Transcript

Example 8 If sin (A – B) = 1/2 , cos (A + B) = 1/2 , 0° ∠ A + ∠ B ≤ 90° , A > B, find A and B. Given data, sin (A – B) = 𝟏/𝟐 But we know that sin 30° = 1/2 Thus, sin (A – B) = sin 30° A – B = 30° cos (A + B) = 𝟏/𝟐 But we know that cos 60° = 1/2 Thus cos (A + B) = cos 60° A + B = 60° Our equations are A − B = 30° …(1) A + B = 60° …(2) Adding (1) and (2) A – B + A + B = 60° + 30° 2A = 90° A = (90°)/2 A = 45° Putting A = "45°" in (2) A + B = 60° 45° + B = 60° B = 60° − 45° B = 15° Hence, A = 45° , B = 15°

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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 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.