Find area bounded between `y = cos^(-1)x` and `y`-axis between `y = pi/2` and `y = pi`.

Explanation

To find the area bounded between the curve \( y = \cos^{-1} x \) and the \( y \)-axis between \( y = \frac{\pi}{2} \) and \( y = \pi \), we can follow these steps:

### Step 1: Understand the curves and the area to be calculated
The curve \( y = \cos^{-1} x \) is defined for \( x \) in the interval \([-1, 1]\). The area we want to find is bounded by this curve, the \( y \)-axis, and the horizontal lines \( y = \frac{\pi}{2} \) and \( y = \pi \).

### Step 2: Sketch the graph
1. Draw the \( y \)-axis.
2. Plot the horizontal lines \( y = \frac{\pi}{2} \) and \( y = \pi \).
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