

An Introduction to Euler’s Theorem
Euler’s theorem for Homogeneous Functions is used to derive a relationship between the product of the function with its degree and partial derivatives of it.

Euler’s Theorem
In this article, we will first discuss the statement of the theorem followed by the mathematical expression of Euler’s theorem and prove the theorem. We will also discuss the things for which Euler’s Theorem is used and is applicable. A brief history of mathematician Leonhard Euler will also be discussed after whom the theorem is named so.
History of Leonhard Euler
Image:
Leonhard Euler,
Name: Leonhard Euler
Born: 15 April 1707
Died: 18 September 1783
Statement of Euler’s Theorem
Euler's theorem states that if
Here, we will be discussing 2 variables only. So, if
Proof of Euler’s Theorem
Proof:
Let
Now, we know that
This is because when
This means that
Now, we will consider the above equations for degree 1.
where
Now, we will differentiate the equation [3] partially w.r.t.
Again, we will differentiate the equation [4] partially w.r.t.
Now, we will substitute
Multiplying the terms, we get
Now, we will substitute
Multiplying the terms, we get
We will now differentiate the equation [1] partially w.r.t.
Partial differentiation of
Now, we will differentiate the equation [1] partially w.r.t.
Partial differentiation of
Now, we will differentiate the equation [2] partially w.r.t.
Since
We will substitute
Using the result of equations [7] and [8], we can write the above equation as
We will again substitute
Hence proved.
Limitations of Euler's Theorem
Euler’s Theorem cannot be applied to non-homogeneous differential equations. It is only applicable to homogeneous differential equations.
Euler’s Theorem is very complex to understand and needs knowledge of ordinary and partial differential equations.
Application of Euler’s Theorem
Euler’s theorem has wide application in electronic devices which work on the AC principle.
Euler’s formula is used by scientists to perform various calculations and research.
Solved Examples
1. If
Ans:
Given
We can say that
is a homogeneous function of degree
By Euler's Theorem,
2. If
Ans:
Given that
Change into an exponential function.
Let
By Euler's Theorem,
Hence Proved.
3. If
Ans:
Given that
Important Formulas to Remember
The function
$f(\lambda x, \lambda y)=\lambda^{n} f(x, y), \text { for any non zero constant } \lambda .$
Here,
If
Conclusion
Euler’s Theorem has a wide range of applications in daily life and it is a fundamental tool of algebra. In this article, we have discussed Euler's theorem and its proof along with its applications of it in daily life.






FAQs on Euler’s Theorem for Homogeneous Functions
1. What is the difference between Euler Formula and Euler’s Formula for Homogeneous Equations? Discuss their similarity if any.
Euler's Formula explains the relationship between trigonometric functions and complex exponentials, i.e.,
2. Is there any Euler Formula for cubes? If yes, is it related to Euler’s Formula for Homogeneous Equations?
Yes, there is an Euler formula for cube. No, it is not related to Euler’s formula for homogeneous equations. We have different Euler’s theorems and formulas and the Euler formula for cube is used in the case of complex polyhedron 3-D figures. Euler’s formula for cube is used to derive relationships between edges, vertices, and faces of 3-D figures. The relation is given as F+V=E+2, where F, E, and V represent the Faces, Edges, and Vertices, respectively, of the cube.
3. Is Euler’s Formula only applicable for 2 variable homogeneous equations?
No, Euler’s Formula can be applied for homogeneous equations in any number of independent variables. The only condition to satisfy Euler’s formula is that the equation should be homogenous and the variables should be independent of each other. Proof of the theorem for any number of variables can be obtained using the generalisation of proof for two independent variables which we have discussed in the above article. Proof using generalisation can be obtained using the principle of Principal Method Induction.

















