Lösung 2.1:8c
Aus Online Mathematik Brückenkurs 1
K (Lösning 2.1:8c moved to Solution 2.1:8c: Robot: moved page) |
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- | {{ | + | When we come across large and complicated expressions, we have to work step by step; |
- | < | + | |
- | {{ | + | as a first goal, we can multiply the top and bottom of the fraction |
- | {{ | + | |
- | < | + | |
- | {{ | + | <math>\frac{1}{1+\frac{1}{1+x}}</math> |
+ | |||
+ | |||
+ | by | ||
+ | <math>1+x</math>, so as to reduce it to an expression having one fraction sign: | ||
+ | |||
+ | |||
+ | <math>\begin{align} | ||
+ | & \frac{1}{1+\frac{1}{1+\frac{1}{1+x}}}=\frac{1}{1+\frac{1}{1+\frac{1}{1+x}}\centerdot \frac{1+x}{1+x}}=\frac{1}{1+\frac{1+x}{\left( 1+\frac{1}{1+x} \right)\left( 1+x \right)}} \\ | ||
+ | & \\ | ||
+ | & =\frac{1}{1+\frac{1+x}{1+x+\frac{1+x}{1+x}}}=\frac{1}{1+\frac{1+x}{1+x+1}}=\frac{1}{1+\frac{x+1}{x+2}} \\ | ||
+ | \end{align}</math> | ||
+ | |||
+ | |||
+ | The next step is to multiply the top and bottom of our new expression by | ||
+ | <math>x+2</math>, | ||
+ | so as to obtain the final answer, | ||
+ | |||
+ | |||
+ | <math>\begin{align} | ||
+ | & \frac{1}{1+\frac{x+1}{x+2}}\centerdot \frac{x+2}{x+2}=\frac{x+2}{\left( 1+\frac{x+1}{x+2} \right)\left( x+2 \right)}=\frac{x+2}{x+2+\frac{x+1}{x+2}\left( x+2 \right)} \\ | ||
+ | & \\ | ||
+ | & \frac{x+2}{x+2+x+1}=\frac{x+2}{2x+3} \\ | ||
+ | & \\ | ||
+ | \end{align}</math> |
Version vom 13:52, 16. Sep. 2008
When we come across large and complicated expressions, we have to work step by step;
as a first goal, we can multiply the top and bottom of the fraction
\displaystyle \frac{1}{1+\frac{1}{1+x}}
by
\displaystyle 1+x, so as to reduce it to an expression having one fraction sign:
\displaystyle \begin{align}
& \frac{1}{1+\frac{1}{1+\frac{1}{1+x}}}=\frac{1}{1+\frac{1}{1+\frac{1}{1+x}}\centerdot \frac{1+x}{1+x}}=\frac{1}{1+\frac{1+x}{\left( 1+\frac{1}{1+x} \right)\left( 1+x \right)}} \\
& \\
& =\frac{1}{1+\frac{1+x}{1+x+\frac{1+x}{1+x}}}=\frac{1}{1+\frac{1+x}{1+x+1}}=\frac{1}{1+\frac{x+1}{x+2}} \\
\end{align}
The next step is to multiply the top and bottom of our new expression by
\displaystyle x+2,
so as to obtain the final answer,
\displaystyle \begin{align}
& \frac{1}{1+\frac{x+1}{x+2}}\centerdot \frac{x+2}{x+2}=\frac{x+2}{\left( 1+\frac{x+1}{x+2} \right)\left( x+2 \right)}=\frac{x+2}{x+2+\frac{x+1}{x+2}\left( x+2 \right)} \\
& \\
& \frac{x+2}{x+2+x+1}=\frac{x+2}{2x+3} \\
& \\
\end{align}