Express $\int _ { 1 } ^ { 4 } \left( 2 x - \frac { 1 } { x ^ { 2 } } \right) d x$

Essay

Express $\int _ { 1 } ^ { 4 } \left( 2 x - \frac { 1 } { x ^ { 2 } } \right) d x$ as the limit of a sum.