Odpowiedź:
Szczegółowe wyjaśnienie:
sin²15° + cos²30 + sin²75° + cos60° =
ponieważ sin15° = sin(90°-75°) = cos75° czyli:
sin²15° + cos²30 + sin²75° + cos60° = cos²75° + cos²30° + sin²75° + cos60 =
= (sin²75° + cos²75°) + cos²30° + cos60° = 1 + (√3/2)² + 1/2 =
3/2 + 3/4 = 6/4 + 3/4 = 9/4 = 2 1/4
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Odpowiedź:
Szczegółowe wyjaśnienie:
sin²15° + cos²30 + sin²75° + cos60° =
ponieważ sin15° = sin(90°-75°) = cos75° czyli:
sin²15° + cos²30 + sin²75° + cos60° = cos²75° + cos²30° + sin²75° + cos60 =
= (sin²75° + cos²75°) + cos²30° + cos60° = 1 + (√3/2)² + 1/2 =
3/2 + 3/4 = 6/4 + 3/4 = 9/4 = 2 1/4