Proof of square root properties

In summary, the conversation discusses a proof-based math problem involving the inequality \sqrt{\Sum_i x_i^2} \leq \Sum_i |x_i| \leq \sqrt{n}\sqrt{\Sum_i x_i^2}. The participants suggest squaring both sides of the equation and considering cross terms to find a solution.
  • #1
diracy
20
0

Homework Statement


[itex]\sqrt{\sum}x^{2}_{i}[/itex][itex]\leq[/itex][itex]\sum[/itex]|x[itex]_{i}[/itex]|[itex]\leq[/itex][itex]\sqrt{n}[/itex][itex]\sqrt{\sum}x^{2}_{i}[/itex]

*The sums are all from i=1 to n.*


Homework Equations





The Attempt at a Solution


I'm very new to proof-based math, and just looking for some help to get started with this one. Thanks in advance.
 
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  • #2
For this part
[tex] \sqrt{\Sum_i x_i^2} \leq \Sum_i |x_i|[/tex]

it should be clear
[tex] 0 \leq \sqrt{\Sum_i x_i^2} [/tex]
[tex] 0 \leq \leq \Sum_i |x_i|[/tex]

so squaring both sides could be useful
 
  • #3
I tried that and didn't get far. It seems to my the leftmost inequality is always equal. I must be thinking about it wrong. In what instance would that inequality be less than?
 
  • #4
you should some cross terms like |xi||xj| on in the middle, which don't appear on the left
 

Related to Proof of square root properties

1. What is the proof of the square root property?

The proof of the square root property states that for any positive real numbers a and b, the square root of ab is equal to the product of the square roots of a and b. In other words, √(ab) = √a * √b.

2. Why is the proof of the square root property important?

The proof of the square root property is important because it allows us to simplify complicated square root expressions and solve equations involving square roots. It also serves as a fundamental property in higher level mathematics.

3. How can the proof of the square root property be applied in real life situations?

The proof of the square root property can be applied in various real life situations, such as calculating the area of a square or rectangle, finding the diagonal of a square or rectangle, and solving problems related to engineering, physics, and finance.

4. Is the proof of the square root property valid for negative numbers?

No, the proof of the square root property is only valid for positive real numbers. When dealing with negative numbers, the square root property does not hold and must be approached differently.

5. Are there any exceptions to the proof of the square root property?

Yes, there are some special cases where the proof of the square root property does not hold. This includes imaginary numbers, which involve the use of the imaginary unit i, and irrational numbers, which cannot be simplified into a rational number.

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