Are there functions satisfying $\int f(x)g(x)dx=\int f(x)dx \times \int g(x)dx$
120960
$f,g$ such that $\int fg = \int f \int g$
57938
When do two functions become equal?
106830
are $f(f(x))=f(x)$ and $f(x)=x$ equivalent?
133851
How to arrive at $\int_{0}^{1} f^3(x) \, dx < (\int_{0}^{1} f(x) \, dx)^2$?
80656
Is it possible to iterate a function transfinite times?
14975
Functions satisfying $f:\mathbb{N}\rightarrow\ \mathbb{N}$ and $f(f(n))+f(n+1)=n+2$
81264
Is $[0, 1) \times (0, 1)$ homeomorphic to $(0, 1) × (0, 1)$?
135634
Prove that there exists a smooth map $g\colon R\to R$ such that $f(\cos(t),\sin(t))=(\cos(g(t)),\sin(g(t)))$ and satisfying $g(2π)=g(0)+2\pi q$.
46359
Finding the general integrals of functions like $\frac1{x^n+1}$, $\cos^nx$.
144192
Showing $\int_{\mathbb R} \mid F(x)-G(x)\mid dx = \int_0^1 \mid F^{-1}(u)-G^{-1}(u)\mid du$ with $F$, $G$ CDF functions
107659
Let $f:A \to B$ and $g:B\to A$ be arbitrary functions.
21775
When can a sum and integral be interchanged?
140936
If two integrals are equal, then the functions are the same
146152
Characterising functions $f$ that can be written as $f = g \circ g$?
141024
Generalising integration by parts for the product of more than two functions
70789
Integrating $\ln(x)\times\ln(1-x)$
80199
Do we have always $f(A \cap B) = f(A) \cap f(B)$?