• how to integratr
• ​∫[ne^-x]dx within the limit 2 to infinity

pull out n constant and integrate using fundamental rules of indefinite integral which would give you -n(e^-x) + C. Now remove C and apply limits on [-ne^-x] which would yield n/e^2 as result

 

 

 

if [] denotes greatest integer function then there can be no indefinite integral for ne^-x dx, and if you want definite then it becomes huge and abrupt.....