Proving the Triangle Inequality for Real Numbers

Fairy111
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Homework Statement



For real numbers x(1), x(2), ..., x(n), prove that |x(1) + x(2) +...+x(n)| <= |x(1)|+...|(n)|

Homework Equations


The Attempt at a Solution

Maybe begin with prooving that x <= |x| ? I am not sure how to do this though.
Any help or hints would be great, as I am really stuck on this.
 
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Fairy111 said:

Homework Statement



For real numbers x(1), x(2), ..., x(n), prove that |x(1) + x(2) +...+x(n)| <= |x(1)|+...|(n)|

First of all, one can prove that, for some real numbers a, b, |a + b| <= |a| + |b|. Any ideas how to generalize? Try to use this inequality to show that |a + b + c| <= |a| + |b| + |c|, for some given real numbers, a, b and c.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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