Newton's method(a method to find one root of any differentiable function)

Note: If you are a beginner in programming then this will help you

Today we are going to discuss NEWTON'S METHOD ,if you know basic programming (c,c++,python or java class 11th level according to cbse) then you are definitely going to like this and if not just to stick to it.

It is method based on simple observation obviously by sir Issac Newton,to understand his observation just skip to next line.

Take any function let say f(x) and think of its graph on coordinate axis this function should be differentiable on all points on coordinates axis so initially for simplicity just think of a simple graph(like f(x)=(x^3-1).


Now take any point on x axis (let say x1) and corresponding value of y(i.e f(x1)).

Now draw tangent at (x1,f(x1)),and note the point on x axis which is common to tangent let the value be x2.

Now you have new point i.e (x2,f(x2)) on the chosen function.

Now again draw tangent on this point and note the common point on new tangent and x axis let say x3 and repeat this process some more times.

When you will repeat this you will find that value of x are heading to the root of the function.

If you want to have the general formula it is

Xn+1=Xn-(f(Xn)/f'(Xn))
where x is values on x axis and f(x) is a function and f'(x) is first differentiation of that function.

if you know basic of programming than its program on c++ will look like this




If you want to see the derivation of the general formula just see next image
There are some drawbacks also 

1)If you want to reach the correct value of root you have to choose correct value x1 and number of steps but a good programmer can solve this problem.

2)There is a problem when f'(x)=0,but again a good programmer can solve it.





Comments

Post a Comment

Popular posts from this blog

Positive thinking ....let's give a thought

Questioning the simple one