Newbetuts

There are finitely many maps on nonnegative integers satisfying $\phi(ab)=\phi(a)+\phi(b)$ [duplicate]

Explain Carmichael's Function To A Novice

Understanding Hom functions

Functional Equation simple problem

Continuity of differentiable function $x^2\sin(1/x)$

How many maps $\phi:\Bbb{N}\to\Bbb{N}$ are there with $\phi(ab) = \phi(a)+\phi(b)$?

Finding maxima of a function $f(x) = \sqrt{x} - 2x^2$ without calculus

What exactly is the fixed field of the map $t\mapsto t+1$ in $k(t)$?

The function $f'+f'''$ has at least $3$ zeros on $[0,2\pi]$.

Verifying a proposition on image and preimage: $f(A\cap B)\subseteq f(A)\cap f(B)$ and $f^{-1}(C\cap D)=f^{-1}(C)\cap f^{-1}(D)$

Is a bijective function always invertible?

How to prove Cauchy Criterion for limits

Find all $f: \mathbb{R} \to \mathbb{R}$ such that $(f(x)+y)(f(x-y)+1)=f(f(xf(x+1))-yf(y-1)), \forall x,y \in \mathbb{R}$

If null set is an element of a set then will it belongs to set or subset? [closed]

Mistake in shell function to count even numbers

Show that there is $\xi$ s.t. $f(\xi)=f\left(\xi+\frac{1}{n}\right)$

New posts in functions

Combination of continuous and discontinuous functions

How to compose two functions?

Why does the domain and range of $\sqrt x$ contain only positive real numbers?

$f(A \cap B)\subset f(A)\cap f(B)$, and otherwise?

There are finitely many maps on nonnegative integers satisfying $\phi(ab)=\phi(a)+\phi(b)$ [duplicate]

Explain Carmichael's Function To A Novice

Understanding Hom functions

Functional Equation simple problem

Continuity of differentiable function $x^2\sin(1/x)$

How many maps $\phi:\Bbb{N}\to\Bbb{N}$ are there with $\phi(ab) = \phi(a)+\phi(b)$?

Finding maxima of a function $f(x) = \sqrt{x} - 2x^2$ without calculus

What exactly is the fixed field of the map $t\mapsto t+1$ in $k(t)$?

The function $f'+f'''$ has at least $3$ zeros on $[0,2\pi]$.

Verifying a proposition on image and preimage: $f(A\cap B)\subseteq f(A)\cap f(B)$ and $f^{-1}(C\cap D)=f^{-1}(C)\cap f^{-1}(D)$

Is a bijective function always invertible?

How to prove Cauchy Criterion for limits

Find all $f: \mathbb{R} \to \mathbb{R}$ such that $(f(x)+y)(f(x-y)+1)=f(f(xf(x+1))-yf(y-1)), \forall x,y \in \mathbb{R}$

If null set is an element of a set then will it belongs to set or subset? [closed]

Mistake in shell function to count even numbers

Show that there is $\xi$ s.t. $f(\xi)=f\left(\xi+\frac{1}{n}\right)$