What is #int_1^oo 1/(1+x )-1/xdx#? Calculus Introduction to Integration Definite and indefinite integrals 1 Answer Eddie Jul 16, 2016 # = ln (1/2)# Explanation: #int_1^oo 1/(1+x )-1/xdx# #= [ ln(1+x )- ln x ]_1^oo# #= [ ln((1+x )/x) ]_1^oo# #= [ ln((1/x+1 )/1) ]_1^oo# #= lim_{x to oo} ln((1/x+1 )/1) - ln((1/1+1 )/1) # #= lim_{x to oo} ln((1/x+1 )/1) - ln((1/1+1 )/1) # #= ln 1 - ln 2 = ln (1/2)# Answer link Related questions What is the difference between definite and indefinite integrals? What is the integral of #ln(7x)#? Is f(x)=x^3 the only possible antiderivative of f(x)=3x^2? If not, why not? How do you find the integral of #x^2-6x+5# from the interval [0,3]? What is a double integral? What is an iterated integral? How do you evaluate the integral #1/(sqrt(49-x^2))# from 0 to #7sqrt(3/2)#? How do you integrate #f(x)=intsin(e^t)dt# between 4 to #x^2#? How do you determine the indefinite integrals? How do you integrate #x^2sqrt(x^(4)+5)#? See all questions in Definite and indefinite integrals Impact of this question 1420 views around the world You can reuse this answer Creative Commons License