Question

Evaluate : (cos 0° + sin 45° + sin 30°) (sin 90° - cos 45° + cos 60°). Prove that,

Answer 1

Question :-

• Evaluate : (cos 0° + sin 45° + sin 30°) (sin 90° - cos 45° + cos 60°)

Values Used :-

→ cos0° = 1

→ sin45° = (1/√2)

→ sin30° = (1/2)

→ sin90° = 1

→ cos45° = 1/(√2)

→ cos60° = (1/2)

Answer :-

Putting All These Values we get,

→ (cos 0° + sin 45° + sin 30°) * (sin 90° - cos 45° + cos 60°)

→ [ 1 + (1/√2) + 1/2 ] * [ 1 - (1/√2) + 1/2 ]

→ [ 3/2 + 1/√2 ] * [ 3/2 - 1/√2 ]

Now using , (a + b) * (a - b) = a² - b² , we get,

→ (3/2)² - (1/√2)²

→ (9/4) - (1/2)

→ (9 - 2) /4

→ (7/4) (Ans).

Answer 2

Answer:

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