Trigonometric Equations

We are given the equation in the interval .
To solve it, we first need to express in terms of .
Let , so that .
The equation becomes: Using the identity for : The equation becomes: Rearranging the equation: This is a quadratic equation in . Using the quadratic formula: The possible values of are approximately: For the first value, , so . For the second value, , so .

The correct option is (C) :

We are given: We know that: Now, substitute this into the given equation: Simplifying this: Now, divide both sides by 2: Now, taking the sine of both sides:
Thus, the value of is .