
perspective and help to catch up on Modern Physics. You can find more Numerical methods tutorial using MATLAB here.A PERSONAL NOTE ABOUT “ATOMIC AGE PHYSICS”: Being fortunate to have all liberal arts courses behind while starting at ENMU the study of Physics and Math, time was spent on outside class readings for info and inspiration. If you have questions regarding secant method or its MATLAB code, bring them up from the comments section. The complete calculation and iteration of secant method (and MATLAB program) for the given function is presented in the table below: The same function f(x) is used here x 0 =0 and x 1 = -0.1 are taken as initial approximation, and the allowed error is 0.001.į(x 1) = cos(-0.1) + 2 sin(-0.1) + ( -0.1 ) 2 = 0.8053 and Lets perform a numerical analysis of the above program of secant method in MATLAB.
SINE COSINE FREEMAT CODE
Here’s a sample output of the above MATLAB code for secant method: The program uses the secant formula (aforementioned in the mathematical derivation) to calculate the root of the entered function. Then, the approximate guess values and desired tolerance of error are entered to the program, following the MATLAB syntax.

In this program for secant method in Matlab, first the equation to be solved is defined and assigned with a variable ‘a’ using inline( ) library function. N=input('Enter allowed Error in calculation: ') X(2)=input('Enter second point of guess interval: ') X(1)=input('Enter first point of guess interval: ') Secant Method in MATLAB: % Secant Method in MATLAB If X-axis is tangential to the curve, it may not converge to the solution.The method fails to converge when f(x n) = f(x n-1).In this method, there is no need to find the derivative of the function as in Newton-Raphson method.So, secant method is considered to be a much faster root finding method. Its rate of convergence is more rapid than that of bisection method.This is the required formula which will also be used in the program for secant method in Matlab.Īdvantages of Secant Method over other Root Finding Methods: we end up with the following expressions: Now, considering this new x as x 2, and repeating the same process for x 2, x 3, x 4. Substituting y = 0 in the above equation, and solving for x, we get: If x be the root of the given equation, it must satisfy: f(x) = 0 or y= 0. The equation of this secant line is given by: For that, it uses succession of roots of secant line in the curve.Īssume x 0 and x 1 to be the initial guess values, and construct a secant line to the curve through (x 0, f(x 0)) and (x 1, f(x 1)). root of the equation that represents the curve) as exactly as possible.


Secant method estimates the point of intersection of the curve and the X- axis (i.e. Mathematical Derivation of Secant Method:Ĭonsider a curve f(x) = 0 as shown in the figure below: Here, we’ll go through a program for Secant method in MATLAB along with its mathematical background and a numerical example. Previously, we talked about secant method vis-à-vis C program and algorithm/flowchart for the method.

SINE COSINE FREEMAT FREE
But, being free from derivative, it is generally used as an alternative to the latter method. During the course of iteration, this method assumes the function to be approximately linear in the region of interest.Īlthough secant method was developed independently, it is often considered to be a finite difference approximation of Newton’s method. Secant method is an iterative tool of mathematics and numerical methods to find the approximate root of polynomial equations.
