numerical analysis
Bairstow method

why the first initial guess doesn't lead us to answer always ???

Question

numerical analysis
Bairstow method

why the first initial guess doesn't lead us to answer always ???

experimentx · Answer

*

anonymous · Answer

see u man

anonymous · Answer

@Mikael  see this plz

anonymous · Answer

which we use for finding all roots of a polynomial...help would be appreciated

anonymous · Answer

how our initial guess increases the rate of convergence

anonymous · Answer

Ok I will have to read more and think. Basically there should be a procedure that deals with quadratic root troubles. Initial guess is small change , forget it.
I have some idea but have to test it. 
Imagine that qudr. root is NOT quadratic root. How ? Several ways are possible - you invent, and I invent....

anonymous · Answer

Then we talk.

anonymous · Answer

in 1-2 days.

anonymous · Answer

thank u...i'll check this :)

anonymous · Answer

@mahmit2012

anonymous · Answer

Wait, @mukushla  I think I might know.

anonymous · Answer

Bairstow's method relies on newton's method to calculate the quadratic's coeffs, right?

anonymous · Answer

yeah we extract quadratics from a polynomial and then solve for all of its roots...

anonymous · Answer

But newton's method essentially makes the assumption that
$$\Delta y = \Delta x dy$$

anonymous · Answer

So if I have some function where the tangent line (dy/dx) has a slope negative to the actual secant line (delta y/delta x) that it's approximating, then you'll get farther from where you started.

anonymous · Answer

Ex:|dw:1349025207545:dw|