# int_{8}^{21}f(x)dx-int_{8}^{11}f(x)dx=int_{a}^{b}f(x)dx Question
Integrals $$\int_{8}^{21}f(x)dx-\int_{8}^{11}f(x)dx=\int_{a}^{b}f(x)dx$$ 2021-02-09
$$\int_{8}^{21}f(x)dx-\int_{8}^{11}f(x)dx=\int_{a}^{b}f(x)dx=\int_{8}^{11}f(x)dx+\int_{8}^{21}f(x)dx=\int_{11}^{21}f(x)dx$$
So a=11, b=21

### Relevant Questions $$\int_{b}^{a}x^{7}dx$$ $$\displaystyle{\int_{{{b}}}^{{{a}}}}{x}^{{{7}}}{\left.{d}{x}\right.}$$ a) If $$\displaystyle f{{\left({t}\right)}}={t}^{m}{\quad\text{and}\quad} g{{\left({t}\right)}}={t}^{n}$$, where m and n are positive integers. show that $$\displaystyle{f}\ast{g}={t}^{{{m}+{n}+{1}}}{\int_{{0}}^{{1}}}{u}^{m}{\left({1}-{u}\right)}^{n}{d}{u}$$
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(R) such that {p(x), q(x), r(x)} is an orthogonal set. Evaluate the following definite integrals.
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