Q48 / 155 · WBJEE 2020 · Mathematics

Let $f$, be a continuous function in $[0,1]$, then $\lim_{n \rightarrow \infty} \sum_{j=0}^n \frac{1}{n} f\left(\frac{j}{n}\right)$ is

  • A
    $\frac{1}{2} \int_{0}^{\frac{1}{2}} \mathrm{f}(\mathrm{x}) \mathrm{dx}$
  • B
    $\int_{\frac{1}{2}}^{1} \mathrm{f}(\mathrm{x}) \mathrm{dx}$
  • Correct answer
    C
    $\int_{0}^{1} f(x) d x$
  • D
    $\int_{0}^{\frac{1}{2}} \mathrm{f}(\mathrm{x}) \mathrm{dx}$

Solution

Figure \(\lim _{n \rightarrow \infty} \sum_{i=0}^{n} \frac{1}{n} f\left(\frac{i}{n}\right)\) Let \(1 / n \rightarrow d x\)

Hence, the correct answer is option: 'C'.

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