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Question
(1 + sin A)(1 – sin A) is equal to ______.
Options
cosec2A
sin2A
sec2A
cos2A
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Solution
(1 + sin A)(1 – sin A) is equal to cos2A.
Explanation:
(1 + sin A)(1 – sin A) = (1)2 – (sin A)2 ......{(a + b)(a – b) = (a2 – b2)}
= 1 – sin2A
= cos2A
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