If 2 cos2 θ - 5 cos θ + 2 = 0, 0° < θ < 90°, then the value of (sec θ + tan θ) is:
Explanation:
2 cos2 θ - 5 cos θ + 2 = 0
2 cos2 θ - 4 cos θ - cos θ + 2 = 0
2 cos θ (cos θ - 2) - 1 (cos θ - 2) = 0
(cos θ - 2) (2 cos θ - 1) = 0
cos θ = 2 or cos θ = 12
cos θ = 2 is not possible.
So, cos θ = 12
sec θ = 2
tan θ = sec2θ-1 = 4-1 = 3
∴ (sec θ + tan θ) = 2 + 3
Hence, the correct answer is Option A
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