Question

If 4cos2 – 4cos + 1 = 0 then tan(0 – 15°) =? 1 (a) 1 (b) o (c) V3 (d) √3/2​

Answer 1

Answer:

(c) √3

Step-by-step explanation:

$4 {(cosθ) }^{2} - 4 \cosθ + 1 = 0 \\ = > {(2 \cosθ - 1)}^{2} = 0 \\ = > cosθ = \frac{1}{2} \\ = > \secθ = 2 \\ = > {(tanθ) }^{2}= {(secθ ) }^{2} - 1 \\ = > {(tanθ) }^{2} = 4 - 1 \\ tanθ = \sqrt{3}$