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Mathematik-Online problems:

Problem 121: Exponential Function


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

The function $ f:\mathbb{R}\longrightarrow\mathbb{R}$ shall have the properties
$\displaystyle f(x+y)$ $\displaystyle =$ $\displaystyle f(x)\cdot f(y), \qquad {\mbox{for all}} \ x, y\in\mathbb{R}\,,$ (1)
$\displaystyle f(0)$ $\displaystyle \neq$ $\displaystyle f(1).$ (2)

Show that $ f(rx)=f(x)^r$ is true for all $ r\in\mathbb{Q}\,,\, x\in\mathbb{R}$.

Hint: Check at first the case $ r\in\mathbb{N}$.


(Authors: Kimmerle/Höfert)

Solution:


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  automatisch erstellt am 14. 10. 2004