Explicație pas cu pas:
[tex]x - 2 \sqrt{x} + 2 + 2 \sqrt{x} = x + 2[/tex]
[tex]\int _{1}^{3} (x + 2) dx = \int _{1}^{3}x dx +2 \int _{1}^{3} 1 dx \\ = \left(\frac{ {x}^{2} }{2} + 2x\right) |_{1}^{3} = \frac{9}{2} + 6 - \frac{1}{2} - 2 = 4 + 4 \\ = 8 \\ [/tex]
