Is there something fundamental that makes integrals nontrivial to solve?
35032
Why is integration so much harder than differentiation?
29296
Are there any special rules when making a substitution in an integral?
123774
Lesser-known integration tricks
144023
Indefinite integral which is not differentiable
54137
Find a non-negative function on [0,1] such that $t\cdot m(\{x:f(x) \geq t\}) \to 0$ that is not Lebesgue Integrable
125764
Under what conditions does Mathematica give a natural antiderivative when integrating?
140153
Conjectures Involving floor(x)/piecewise continuity with regards to Integration and Differential Equations
24235
Is there a rule of integration that corresponds to the quotient rule?
152336
Any hint to solve given integral $\int_0^{2{\pi}}{{d\theta}\over{a^2\cos^2\theta+b^2\sin^2\theta}}$?
28540
Really advanced techniques of integration (definite or indefinite)
24653
Integral in $n-$dimensional euclidean space
17154
Does a non-trivial solution exist for $f'(x)=f(f(x))$?
112189
Discontinuity in function; order of integration matters
3978
How can you prove that a function has no closed form integral?
85282
Will inverse functions, and functions always meet at the line $y=x$?
133337
A little integration paradox
21857
Seeking methods to solve: $\int_0^\infty \frac{\ln(t)}{t^n + 1}\:dt$