If 2cos2 - 5 cos + 2 = 0, 0º < < 90º, then the value of (sec + tan ) is:
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Correct answer: A
Explanation
The correct answer is option 1 i.e. 2 + .
⇒ 2cos2 - 5 cos + 2 = 0
⇒ 2cos2 - 4 cos - cos + 2 = 0
⇒ 2cos(cos - 2) -1(cos - 2) = 0
⇒ (cos - 2)(2cos - 1)
⇒ cos = 1/2 and 2
cos cannot be beyond 1 so 2 is not possible.
cos = cos60
= 60.
= Now sec60 + tan60
= 2 + .