UPSC » UPSC CSE Study Materials » Mathematics » Points To Remember Of A Monotonic Function

Points To Remember Of A Monotonic Function

Through this text, the reader can get brief about what the monotonic function is and a few other important aspects of it.

Introduction

A monotonic function could be a function that is either entirely nonincreasing or nondecreasing. A function is monotonic if its first derivative doesn’t change significantly.

The term monotonic may additionally be used to describe set functions that map subsets of the domains to non-decreasing values of the codomains.

What Is Monotonicity?

The monotonicity of a function helps us in determining whether the function is increasing or decreasing in nature. A function is increasing when it shows in the graph an upward direction from point a to point b. If for any x1 and x2 in I, x1 is a smaller amount than x2 implies that f(x1) is a smaller amount than f(x2). This says that when x1 is a smaller amount than x2, then the function evaluated at x1 is a smaller amount than the function evaluated at x2.

A function is decreasing when it forms a downward direction line from point a to point b. Again, the technical definition says that a function is decreasing on an interval I if for any x1 and x2 in I, x1 is a smaller amount x2 implies that f(x1) is larger than f(x2). In other words, a function is decreasing on an interval I when it is the case that whenever x1 is a smaller amount than x2, f(x1) is larger than f(x2).

How To Find Monotonicity Of A Function?

The major question arises about how to find the monotonicity of a function. it can be found with the help of the following points.

  • Monotonicity check at one point: – At any point on the graph we can check that the monotonically increasing or decreasing function can be checked by the help of drawing a tangent on a particular point on the graph and observing the point that whether the tangent is making an acute angle or it is making an obtuse angle with the x-axis on the graph. If it is making an acute angle then it is known that the function is monotonically increasing and if it is making an obtuse angle with an x-axis then it is known that the function is monotonically decreasing at that point. 

  • Monotonicity For An Interval: – Let p, and q be the two-interval points and f(x) be the function.

            The function is monotonically increasing if the first derivative of f(x),f1(x) >= 0.

            The function is monotonically decreasing if the first derivative of f(x),f1(x) <= 0.

            The function is monotonically constant if the first derivative of f(x),f1(x) = 0.

What Is A Monotonic Function?

A Monotonic Function is stated as any given Function that follows one of the four cases mentioned above. The Monotonic term is derived from the two terms first one is Mono refers to at least one and tonic refers to tone from these two-term we get monotonic. After you say that a Function is non-Decreasing, does it mean that it’s increasing? The solution is not any. It may also mean that the Function doesn’t vary in the least. In simpler words, the Function has a continuing value for a specific interval. Confirm to not confuse non-Decreasing with Increasing.

Increasing Function

If x1 < x2 and F(x1) < F(x2) then function is understood as increasing function or strictly increasing function. It can be described as after we can see an upward line going through the graph or if the second point within the graph is larger than the primary point within the graph then it’s called the increasing function. Or we can say that if the line is going from point a to point b in an upward direction then this form is known as the increasing function

Decreasing Function

For F(x) = e (-x)

If x1 < x2 and F(x1) > F(x2) then function is thought as decreasing function or strictly decreasing function. It can be described as after we are ready to see a downward line going through the graph or if the second point within the graph is smaller than the primary point within the graph then it’s called decreasing function. Or we can say that if the line is going from point a to point b in a downward direction then this form is known as the decreasing function.

Conclusion

The monotonicity of a function helps us in determining whether the function is increasing or decreasing in nature. A function is increasing when it shows an upward move from a certain point to another point. In technical terms, a function is increasing on an interval when a function is increasing on its entire domain or decreasing on its entire domain, we are saying that the function is strictly monotonic and that we call it a monotonic function. A Monotonic Function is spoken as any given Function that follows one in all the four cases mentioned above. Monotonic generally has two terms in it. Mono refers to at least one and tonic refers to the tone

 
faq

Frequently asked questions

Get answers to the most common queries related to the UPSC Examination Preparation.

What is monotonicity?

Ans. The monotonicity of a function tells us if the function is increasing or decreasing. A function is increasing w...Read full

What is a monotonic function?

Ans. The Monotonic term is derived from the two terms first one is Mono refers to at least one and tonic refers to t...Read full

What is an increasing function?

Ans. If the second point in the graph is higher than the first point then we can say that is an increasing function....Read full

What is the decreasing function?

Ans. If the second point in the graph is below then the first point is known as the decreasing function. It can be d...Read full