91Ó°ÊÓ

Integration is a fundamental concept in calculus. It helps us find the area under a curve. There are different types of integrals, but we focus on definite integrals.

A definite integral computes the accumulation of quantities, such as area, between two bounds. We use the notation \(\int_{a}^{b} f(x) \, dx \) to indicate the integral of \( f(x) \) from \( a \) to \( b \).

To solve an integral:

• Identify the bounds \( a \) and \( b \).
• Determine the function \( f(x) \).
• Integrate the function and apply the bounds.

We subtract the value of the antiderivative at \( a \) from its value at \( b \). This gives us the accumulated area between \( a \) and \( b \).

Piecewise functions consist of different expressions based on the input's value. They are written as multiple sub-functions, each with a specific domain.

The exercise involves a piecewise function defined as \( y = \text{{max}}\{2-x, 2, 1+x\} \). This 'max' function selects the maximum value among its components for each \( x \).
For instance, within a specific range:

• For \( -1 \leq x < 0 \), the function \( y = 2 - x \) provides the highest value.
• For \( 0 \leq x \leq 1 \), the function \( y = 2 \) provides the highest value.

This segmentation helps us identify the correct function to integrate over each interval.

A definite integral calculates the area under a curve between two specific points on the x-axis. We denote it with two limits, \( a \) and \( b \), as in \(\int_{a}^{b} f(x) \, dx \).

In our exercise, we split the integral into segments based on the dominant piecewise function.

• For \( -1 \leq x < 0 \), we integrate \( 2 - x \).
• For \( 0 \leq x \leq 1 \), we integrate \( 2 \).

Each integral gives the area of its segment. Summing these areas provides the total area under our piecewise-defined curve within the given range.

For example, integrating \( 2 - x \) from \( -1 \) to \( 0 \) and \( 2 \) from \( 0 \) to \( 1 \) leads to:
\( \text{{Total Area}} = \int_{-1}^{0} (2 - x) \, dx + \int_{0}^{1} 2 \, dx = \frac {3}{2} + 2 = \frac{7}{2} \). This final value represents the total area covered by the curve.