Answer:
third option:
Step-by-step explanation:
We write the sin(2x) using the property of sin of the double angle:
and replace the expression on the left of the given equation by this:
now we notice that if equals zero, the equation becomes true. Therefore all of the values that make are solutions. That is .
Now, in the case is NOT zero, we can divide both sides of the equation by it, ending up with a simple answer:
and in the interval between 0 and the solutions to this are:
So we found a total of four solutions: