Consider the following statement(1) Value of Cos26° + Cos220 °+ Cos2

1.	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?1. Only 12. Only 23. Only 34. 1, 2 and 3
Answer» Correct Answer - Option 4 : 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

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?1. Only 12. Only 23. Only 34. 1, 2 and 3

Answer» Correct Answer - Option 4 : 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