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Consider the following statement (1) Value of Cos26° + Cos220 °+ Cos284 °+ Cos270° is 2. (2) Sin 45° = Cos 45°. (3) Sin 0° + Cos 0° is 1. Which of the above statement(s) is/are right?

Consider the following statement (1) Value of Cos26° + Cos220 °+ Cos284 °+ Cos270° is 2. (2) Sin 45° = Cos 45°. (3) Sin 0° + Cos 0° is 1. Which of the above statement(s) is/are right? Correct Answer 1, 2 and 3

Concept

Sin2A + Cos2A = 1

Calculation

Statement 1

Cos2(90°– 84°) + Cos2 (90° – 70°) + Cos284° + Cos2 70°

⇒  Sin284° + Sin270° + Cos284 °+ Cos270°

⇒  Sin284 °+ Cos284 °+ Sin270°+ Cos270°

⇒  1 + 1

⇒  2

Statement 2

Sin 45° = (1/√2)

Cos 45° = (1/√2)

Statement 3

Sin 0° + Cos 0°

⇒   0 + 1

⇒   1

Hence, every statement is right

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