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January 31, 2015

January 31, 2015

Posted by **Lenny** on Tuesday, December 13, 2011 at 7:19pm.

(θ) - 13 cos(θ) + 6 = 0 that is(are) in the

interval (0,π/2) is one of following

a. {π/6} b. {π/3}

c. {π/4}

d. {π/3, π/6}

e. {π/6, π/4}

- Trig -
**Steve**, Wednesday, December 14, 2011 at 11:31amThis is just a quadratic in cosθ

2cos^2θ - 13cosθ + 6 = 0

(2cosθ - 1)(cosθ - 6) = 0

so,

2cosθ = 1

cosθ = 1/2

θ = π/3

or,

cosθ = 6

no solutions there

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