First, we use the property that sin(−x)=−sinx. Thus −sinx=sin(−x). Therefore, the function becomes y=sin−1(sin(−x)). We know that sin−1(sinx)=x if −2π≤x≤2π. However, since we have sin−1(sin(−x)), we want to determine the values of x for which −2π≤−x≤2π. Multiplying by −1, we get 2π≥x≥−2π, which is the same as −2π≤x≤2π. Therefore, for −2π≤x≤2π, we have sin−1(sin(−x))=−x. Now, let's consider the interval 2π≤x≤23π. In this interval, we can write x=π−x′, so x′=π−x. Note that if 2π≤x≤23π, then −2π≤x′≤2π is false. For example, if x=π, then x′=0, which is true, but if x=23π, then x′=−2π which is also true. If x=2π, x′=2π. Since sinx=sin(π−x), we have sin(−x)=sin(π+x). However, since the range of sin−1 is [−π/2,π/2], we want to express −sinx as siny for some y∈[−π/2,π/2]. We know −sinx=sin(−x). If we are considering the interval 2π≤x≤23π, then −23π≤−x≤−2π. Let z=x−π. Then x=z+π. If 2π≤x≤23π, then −2π≤z≤2π. We have sin(−x)=sin(−(z+π))=sin(−z−π)=−sin(z+π)=−(−sinz)=sinz. Thus sin(−x)=sin(x−π). So, y=sin−1(sin(−x))=sin−1(sin(x−π)). Since −2π≤x−π≤2π when 2π≤x≤23π, we have sin−1(sin(x−π))=x−π. So we have:
y=−x for −2π≤x≤2π y=x−π for 2π≤x≤23π Notice that the function is periodic with period 2π. Thus, we want to find the function in the interval [−π/2,23π]. The function is defined as:
y =
\begin{cases}
-x & -\frac{\pi}{2} \le x \le \frac{\pi}{2} \\
x - \pi & \frac{\pi}{2} \le x \le \frac{3\pi}{2}
\end{cases}
The graph repeats this pattern every 2π.