Secant line

The word secant (Latin: secare = " cut") referred to in the planar geometry and in analysis a straight line passing through two points of a curve.

Circular secant

In elementary geometry is meant by a secant is a straight line that intersects a circle in two points. A straight line exactly one point in common with the circle, ie tangent; a line that has no common point with the circle is called Passante. A secant line that passes through the center of the circle is called the center.

Is a straight line if and secant of a given circuit when the distance of the circular center point of the straight line is smaller than the radius of the circle. Is the distance equal to the radius, there is a tangent; it is greater than the radius, there is a Passante.

The portion of the secant which is within the circle is tendon. The longest chords of a circle are the ones that go through the center of the circle. These and their lengths are referred to as the diameter of the circle.

The Sekantensatz describes the relationship of the section lengths of two Kreissekanten that intersect outside the circle, the secant - tangent theorem, the relationship between intersecting tangent and secant.

Kurvensekante

General is also called a straight line passing through ( at least) two points of a curve, for example, a function graph runs, a secant. Their pitch is called Sekantensteigung. The slope of the secant through two points of the graph of the function is given by

This is just the difference quotient of the function in the interval. It plays an important role in the differential calculus in the definition of the derivative. If you hold into place and leaves the body to "migrate " the secant approaches at a differentiable function through the points and the tangent to the function graph in point. The Sekantensteigung converged thereby against the slope of the tangent, which is the derivative of the function at the point

The secant method is a numerical approximation method for determining a zero point using Kurvensekanten.