Question

cos 90°=1-2 sin square 45°=2 cossquare 45 °-1​

Answer 1

cos 90°= 1 - 2 sin² 45°= 2 cos² 45°-1

Answer:

0 = 1 - 2 × (1/√2)² = 2 × (1/√2)² - 1

0 = 1 - 2 × 1/2 = 2 × 1/2 - 1

0 = 1 - 1 = 1 - 1

0 = 0 = 0

Step-by-step explanation:

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