`int (6 + x)/(x^2 + 4)\ dx`

`= int 6/(x^2 + 4)\ dx + int x/(x^2 + 4)\ dx`

`= 3 int 2/(x^2 + 2^2)\ dx + 1/2 int (2x)/(x^2 + 4)\ dx`

`= 3 tan^-1(x/2) + 1/2 log_e (x^2 + 4)\ \ \ (c=0)`

`int (1-cos(10x))\ dx`

 `= int 1-cos (2xx (5x))\ dx`

`= int 1-(2 cos^2 (5x)-1)\ dx`

`= int 2-2 cos^2 (5x)\ dx`

`= int 2 (1-cos^2 (5x))\ dx`

`= 2 int sin^2 (5x)\ dx`

 
`=>  E`