Question

Hi, can anyone please help me with this one:
I have a quadratic equation that I have factorised to (2sinx - 1)(sinx - 1)=0
It came out with two solutions solutions:
sin x = 1/2 or sin x = 1.
I have found out that sin x is positive in the first and second quadrants and that sin π/6 = 1/2
we have two solutions, in the specified interval 0<=x>=2π, corresponding to sin x = 1/2, namely x=π/6 and x =5π/6.
Question: If sin x = 1, why is it specified as π/2