Proof of Cauchy-Schwarz Inequality

In summary, the conversation discusses a homework problem involving the Cauchy-Schwarz inequality. The person tried to use induction but encountered difficulties with summation. The professor suggested using the fact that geometric means are less than or equal to the arithmetic mean, but the person is unsure how to proceed. They question whether to continue with induction or explore a different approach. The suggestion is to look at the inner product of vectors and a scalar to find the desired result.
  • #1
barksdalemc
55
0
I have a homework problem in which I have to prove the Cauchy-Schwarz inequality. I tried to do it by induction, but when I try to do summation to 2, I get a mess of terms. The professor hinted that one can use the fact that geometric means are less than or equal the arithmetic mean, but I can't seem get past just that hint. Should I continue trying induction or am going down the wrong road?
 
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  • #2
The slick way is to look at the inner product of x+a*y with itself, where x,y are vectors and a is a scalar. This must be positive for all a, and picking the right a will give you the result.
 

What is the Cauchy-Schwarz Inequality?

The Cauchy-Schwarz Inequality is a mathematical concept that states that the dot product of two vectors is always less than or equal to the product of their magnitudes. It is also known as the Cauchy-Bunyakovsky-Schwarz Inequality or simply the Cauchy Inequality.

Why is the Cauchy-Schwarz Inequality important?

The Cauchy-Schwarz Inequality is important because it is a fundamental result in mathematics that has many applications in fields such as linear algebra, calculus, and statistics. It is also a key tool in proving other inequalities and theorems.

How is the Cauchy-Schwarz Inequality used?

The Cauchy-Schwarz Inequality is used to show that certain quantities are bounded, or to prove that certain functions or expressions are positive definite. It is also used in optimization problems to find the maximum or minimum value of a function.

What is the proof of the Cauchy-Schwarz Inequality?

The proof of the Cauchy-Schwarz Inequality involves using the Cauchy-Schwarz Identity, which states that the square of the dot product of two vectors is equal to the product of their magnitudes. By manipulating this identity, the Cauchy-Schwarz Inequality can be derived.

Is the Cauchy-Schwarz Inequality always true?

Yes, the Cauchy-Schwarz Inequality is always true. It is a mathematical theorem that has been proven and is accepted as a fundamental result in mathematics. It has been shown to hold for various types of vector spaces and is considered to be a universal truth.

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