# Secant lines

In the field of **geometry** when we refer to a **line** we are referring to the **one-dimensional ****line** that, formed by an **infinite** number of points, extends in the same **direction** . A **secant** line or **straight** , which can also be simply called a secant, is a line that passes through **two points** on a **curve** . When the two points meet or, more precisely, when one approaches the other, the secant line tends to a **tangent line** .

## What is a secant line?

A **secant line** is a line that cuts a **curve** at two **different ****points** which as they get **closer** , and their distance is **reduced** to **zero** , the line then acquires the name of a secant line.

- Definition
- Characteristics of secant lines
- Types of secant lines
- Objects with intersecting lines
- Examples

## Definition

In the area of mathematics we know **intersecting lines** as those lines that are found by **cutting** a **circle** at two **specific points** . As these cutting points get closer, the line also gets closer to the point and because there is only one point that is touching the **circumference** , it is then called a **tangent** . In a general way, we can say that a **secant**** line** is a line that is located in the **same plane** that has to be cut at a **certain point** .

It is important to mention that a line is the **union** of a series of **points** which are ordered in the **same direction** , and this line is given its name by means of a lowercase letter; Depending on the **direction** of the line, they can also be **vertical** , **horizontal** or **inclined** ; and depending on their **relative** position we can find the parallel lines that do not intersect and the secants that do, forming **90º angles** .

The secant line is the line that is found connecting **two points** (x, f (x)) and (a, f (a)) on the **Cartesian ****plane** on a curve described by a **function y** = f (x). Give the average rate of change of f from x to.

## Characteristics of secant lines

The main characteristics of secant lines are the following:

- If the two
**points**are very close**together**, the secant line is almost the same as a**tangent**line . - When the lines
**intersect**, they give rise to four different regions called**angles**. - Secant lines are not
**equidistant**. - They are straight lines that
**intersect**each other.

## Types of secant lines

Regarding the types or the **classification** of secant lines, we can say that they can be classified as **oblique** and **perpendicular** . **Oblique** secant lines can be defined as those lines that intersect at a certain point forming **angles ****equal to** two by two, that is, they form two equal or similar **obtuse angles** and two equal or similar **acute angles** because they are **opposite** or opposite.

Secondly, we find the **perpendicular** lines , these types of lines also intersect at a single point with the peculiarity that the angles that are formed in it are **straight,** that is, they are 90º angles and, furthermore, the four are totally **equal** or **similar** . On the contrary, when two lines do not have any **points** in **common** , and they are in the same plane, they are called **parallel lines** .

In **abstract mathematics** , the points connected by a secant line can be **real** or **complex ****imaginary ****conjugates** .

## Objects with intersecting lines

We can observe intersecting lines in the world around us. Basically anywhere you see a **curve** with a **line** that **intersects** two or more points, we have a secant line.