Maximum of rational functions

Therefore, the maximum values of (dx^2+ex+f)/(ax^2+bx+c) and (gx+h)/(ax^2+bx+c) cannot be multiplied together to get the maximum of the whole expression.
  • #1
japam
39
0
Suppose 2 cuadratic functions: ax^2+bx+c, dx^2+ex+f. Suppose that the first one is upside with its minimum above the x line reference, and the second one is downside with its maximum above the x reference, and suppose that the two functions intersect at two points that pass through straight line gx+h.
My question is
¿could the maximum of (dx^2+ex+f)/(ax^2+bx+c), be splitted as the
max( (dx^2+ex+f)/(gx+h))*max((gx+h)/(ax^2+bx+c))?

I don't know how to put drawings here, but i hope the argument has been clear to understand
I was tryng some numeric examples in my pc and the result was positive, but i don't know what is the general proof. Thanks for your comments
 
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  • #2
No, this cannot be done. The maxima don't even need to exist. Test it on ##-x^2+4\, , \,3x^2## with ##y=3## as straight. And you must not multiply infinities.
 
  • #3
japam said:
Suppose 2 cuadratic functions: ax^2+bx+c, dx^2+ex+f. Suppose that the first one is upside with its minimum above the x line reference, and the second one is downside with its maximum above the x reference, and suppose that the two functions intersect at two points that pass through straight line gx+h.
My question is
¿could the maximum of (dx^2+ex+f)/(ax^2+bx+c), be splitted as the
max( (dx^2+ex+f)/(gx+h))*max((gx+h)/(ax^2+bx+c))?

I don't know how to put drawings here, but i hope the argument has been clear to understand
I was tryng some numeric examples in my pc and the result was positive, but i don't know what is the general proof. Thanks for your comments
That would only work if max was reached for the same values of x, e.g., Max ##sinx \neq ## (Max ## {xsinx})## (Max## \frac {1}{x})## ( for one, last expression is unbounded, while ##sinx## has ##1## as its max.
 

Related to Maximum of rational functions

What is a rational function?

A rational function is a mathematical function that can be written as a ratio of two polynomials, where the denominator is not equal to zero. It can also be described as a fraction of two polynomial expressions.

What is the maximum of a rational function?

The maximum of a rational function is the highest point on the graph of the function, also known as the global maximum. It represents the largest output value that the function can reach.

How do you find the maximum of a rational function?

To find the maximum of a rational function, you can use calculus techniques such as differentiation and critical point analysis. The maximum will occur at a critical point where the derivative of the function is equal to zero or does not exist.

Can a rational function have more than one maximum?

Yes, a rational function can have multiple maximum points if it has multiple critical points. This occurs when the function has a horizontal asymptote or when the denominator has multiple roots.

What is the significance of the maximum of a rational function?

The maximum of a rational function is important in understanding the behavior and characteristics of the function. It can be used to find key points on the graph, determine the range of the function, and identify intervals of increase and decrease. It also has practical applications in optimization problems.

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