Q61 / 125 · BITSAT 2021 · Mathematics

$\int_{-a}^{4}\left(x^{8}-x^{4}+x^{2}+1\right) d x=2 \int_{0}^{4}\left(x^{8}-x^{4}+x^{2}+1\right) d x$ then $a=$

  • A
    3
  • Correct answer
    B
    4
  • C
    6
  • D
    8

Solution

If $\mathrm{f}(x)$ is an even function then $\int_{-a}^{a} f(x) d x=2 \int_{0}^{a} f(x) d x$ Here $\mathrm{f}(x)=x^{8}-x^{4}+x^{2}+1$ is an even function, therefore $a=4$.

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

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