Question

sa se afle aria figurii delimitate de dreptele y=0, y=1/3 x, x=1, si x= 3.

Answer 1

  
[tex]\displaystyle A=\int\limits^3_1 { \frac{1}{3} x}\, dx = \left \frac{1}{3}\times \frac{x^2}{2} \right|_{1}^{3} = \left \frac{x^2}{6} \right|_{1}^{3} =\frac{3^2}{6}-\frac{1^2}{6} =\frac{8}{6}=\boxed{\frac{4}{3}} \\ \\ [/tex]