grandes-ecoles 2014 Q1c

grandes-ecoles · France · x-ens-maths__psi Groups Group Homomorphisms and Isomorphisms
Let $E$ be the set of continuous functions from $[0,1]$ to $\mathbb{R}$ equipped with the norm $\|.\|_{\infty}$: $$\|f\|_{\infty} = \max_{x \in [0,1]} |f(x)|$$ We denote by $T$ the application defined on $E$ such that: $$\forall f \in E, \quad \forall x \in [0,1], \quad T(f)(x) = x f\left(\frac{x}{2}\right)$$ Determine $\operatorname{Ker}(T)$ and $\operatorname{Im}(T)$.
Let $E$ be the set of continuous functions from $[0,1]$ to $\mathbb{R}$ equipped with the norm $\|.\|_{\infty}$:
$$\|f\|_{\infty} = \max_{x \in [0,1]} |f(x)|$$
We denote by $T$ the application defined on $E$ such that:
$$\forall f \in E, \quad \forall x \in [0,1], \quad T(f)(x) = x f\left(\frac{x}{2}\right)$$
Determine $\operatorname{Ker}(T)$ and $\operatorname{Im}(T)$.