Check sibling questions

If sin θ – cos θ = 0, then the value of (sin 4 θ + cos 4 θ) is

(A) 1 

(B) 3/4 

(C) 1/2     

(D) 1/4

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Question 16 If sin θ – cos θ = 0, then the value of (sin4 θ + cos4 θ) is (A) 1 (B) 3/4 (C) 1/2 (D) 1/4 Given sin θ – cos θ = 0 sin θ = cos θ This can only happen if θ = 45° Now, sin4 θ + cos4 θ = sin4 45° + cos4 45° = (1/√2)^4+(1/√2)^4 = 2 × (𝟏/√𝟐)^𝟒 = 2 × [(1/√2)^2 ]^2 = 2 × [1/2]^2 = 2 × 1/4 = 𝟏/𝟐 So, the correct answer is (C)

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