Answer:
A
Step-by-step explanation:
We want to solve the equation:
[tex]2\sin^2(x)=\sin(x)[/tex]
For the interval [0, 2π).
First, we can move all the terms to one side. Start off by subtracting sin(x) from both sides:
[tex]2\sin^2(x)-\sin(x)=0[/tex]
We can factor:
[tex]\sin(x)\left(2\sin(x)-1\right)=0[/tex]
By the Zero Product Property:
[tex]\sin(x)=0\text{ or } 2\sin(x)-1=0[/tex]
Solve for each case:
[tex]\displaystyle \sin(x)=0\text{ or } \sin(x)=\frac{1}{2}[/tex]
Use the unit circle to solve:
[tex]\displaystyle x=\left\{0, \frac{\pi}{6},\frac{5\pi}{6}, \pi\right\}[/tex]
Hence, our answer is A.
*Please note that we should not simply divide both sides by sin(x) to acquire 2sin(x) = 1. The problem with the operation is that we are dividing by sin(x), yet we do not know what the value of x is. Thus, one or more values of x may result in sin(x) = 0, and we cannot divide by 0. Hence, we are required to subtract and then factor, unless the question specifically states that sin(x) ≠ 0.
