Biết rằng \({I_1} = \int\li...

B

- Hướng dẫn giải

\({I_1} = \int\limits_0^1 {\left( {x + \sqrt {x + 1} } \right)dx} \\= \left. {\left( {\frac{{{x^2}}}{2} + \frac{2}{3}\sqrt {{{\left( {x + 1} \right)}^3}} } \right)} \right|_0^1 = - \frac{1}{6} + \frac{{4\sqrt 2 }}{3}\\ \Rightarrow a = - 1,b = \frac{4}{3} \Rightarrow a - \frac{3}{4}b = - 2\)