11. The expression \[ \frac{1}{10} \left[ \frac{1}{10} + \frac{2}{10} + \frac{3}{10} + \cdots + \frac{20}{10} \right] \] is a Riemann sum approximation for






Answer is: option2

\( \int_0^2 x \, dx \)

Solution:

Recognize the form of the Riemann sum

The sum inside the brackets is:

\[ \sum_{i=1}^{20} \frac{i}{10} \]

So the full expression becomes:

\[ \frac{1}{10} \sum_{i=1}^{20} \frac{i}{10} \]

This is of the form:

\[ \sum_{i=1}^{n} f(x_i) \Delta x \]

With:

  1. \( \Delta x = \frac{1}{10} \)
  2. \( x_i = \frac{i}{10} \)
  3. \( f(x) = x \)

Therefore, this is a right Riemann sum approximation for the integral:

\[ \int_0^2 x \, dx \]

Because:

  1. The values of \( x_i = \frac{i}{10} \) go from \( \frac{1}{10} \) to \( \frac{20}{10} = 2 \) — 20 subintervals.
  2. It approximates the area under \( f(x) = x \) from \( x = 0 \) to \( x = 2 \).

Option - B

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