Question

Sin²30°+cos²60°-3cos45°+sin90°[Evaluate]

Answer 1

Question : Sin²30°+cos²60°-3cos45°+sin90°[Evaluate]


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Solution :


↪ Sin²30°+cos²60°-3cos45°+sin90°


▶ Note Some Trigonometric Ratio of Angles ➡

↪ Sin 30° = 1/2

↪ Cos 60° = 1/2

↪ Cos 45° = 1/√2

↪ Sin 90° = 0


Substitute the Given Value In Equation!



➡ Sin²30°+cos²60°-3cos45°+sin90°

↪ (1/2)² + (1/2)² - 3[(1/√2) + 0

↪ 1/4 + 1/4 - 3/√2

↪ 2/4 - 3/√2

↪ 1/2 - 3√2

↪√2 - 6 / 2√2

Answer 2

Hi !!

Take the following steps into consideration :-


sin²30° + Cos²60° -3Cos45° + sin90°


=> (1/2 )² + (1/2)² - 3× 1/√2 + 1




1/4 +1/4 -3/√2 +1

=> 6/4 -3/√2

=> 3/2 -3/√2

=> 3( √2-2) /2√2


formula used :-

sin30° = 1/2

cos 60° = 1/2

cos45° = 1/√2

and sin 90° = 1


Hope you get your answer !!!

thanks !!