1. **Problem Statement:** Identify the equation that represents the given graph. 2. **Graph Description:** The graph oscillates between $-1$ and $1$, crosses the y-axis at $y=1$, and is wave-like centered on the origin with x-axis labeled in multiples of $\frac{\pi}{2}$. 3. **Recall the basic trigonometric functions:** - $y = \sin x$ oscillates between $-1$ and $1$, crosses the origin at $(0,0)$. - $y = \cos x$ oscillates between $-1$ and $1$, crosses the y-axis at $y=1$. - $y = \csc x = \frac{1}{\sin x}$ has vertical asymptotes where $\sin x = 0$ and values outside $[-1,1]$. - $y = \sec x = \frac{1}{\cos x}$ has vertical asymptotes where $\cos x = 0$ and values outside $[-1,1]$. 4. **Analyze the graph:** - The graph crosses the y-axis at $y=1$, which matches $y=\cos x$ since $\cos 0 = 1$. - The wave oscillates between $-1$ and $1$, consistent with $\cos x$. - The x-axis labels in multiples of $\frac{\pi}{2}$ align with the periodicity of cosine. 5. **Conclusion:** The equation representing the graph is: $$y = \cos x$$