If triangle ABC is right angled at C, then the value of sec (A + B) is

(a) 0        (b) 1          (c) 2/√3        (d) not defined

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Transcript

Question 5 If triangle ABC is right angled at C, then the value of sec (A + B) is (a) 0 (b) 1 (c) 2/√3 (d) not defined In Δ ABC Sum of angles = 180° ∠ A + ∠ B + ∠ C = 180° Given Δ ABC is right angled at C, So, ∠ C = 90° Therefore, our equation becomes ∠ A + ∠ B + 90° = 180° ∠ A + ∠ B = 180° – 90° ∠ A + ∠ B = 90° Now, sec (A + B) = sec 90° = 1/cos⁡〖90°〗 = 1/0 = Not defined ∴ Correct answer is option (d)

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.