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Question
9 sec2 A − 9 tan2 A = ______.
Options
1
9
8
0
Solution
9 sec2 A − 9 tan2 A = 9.
Explanation:
9 sec2A − 9 tan2A
= 9 (sec2A − tan2A)
= 9 (1) ...[As sec2 A − tan2 A = 1]
= 9
Hence, alternative 9 is correct.
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