Question

Find the values of which satisfy the equation. 2 cos (2B+30°) = -√3 in the domain OP ≤B≤360°​

Answer 1

Answer:

60 and 90

Step-by-step explanation:

$2 \cos(2 \beta + 30) = - \sqrt{3}$

$\cos(2 \beta + 30) = - \frac{ \sqrt{3} }{2}$

$2 \beta + 30 = \cos {}^{ - 1} ( \frac{ - \sqrt{3} }{2} )$

First solution.

$2 \beta + 30 = 150$

$2 \beta = 120$

$\beta = 60$

Second solution

$2 \beta + 30 = 210$

$2 \beta = 180$

$\beta = 90$