Matlab-Bisection-Newton-Secant , finding roots?

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Published on 2012-11-11T11:53:29Z Indexed on 2012/11/11 17:00 UTC
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Hello and thanks in advance for your possible help !

Here's my problem: I have 2 functions

f1(x)=14.*x*exp(x-2)-12.*exp(x-2)-7.*x.^3+20.*x.^2-26.*x+12
f2(x)=54.*x.^6+45.*x.^5-102.*x.^4-69.*x.^3+35.*x.^2+16.*x-4

Make the graph for those 2, the first one in [0,3] and the 2nd one in [-2,2]. Find the 3 roots with accuracy of 6 decimal digits using a) bisection ,b) newton,c)secant.For each root find the number of iterations that have been made. For Newton-Raphson, find which roots have quadratic congruence and which don't. What is the main common thing that roots with no quadratic congruence (Newton's method)?
Why ?

Excuse me if i ask silly things, but i'm asked to do this with no Matlab courses and I'm trying to learn it myself.

There are many issues i have with this exercise .

Questions :

1.I only see 2 roots in the graph for the f1 function and 4-5 (?) roots for the function f2 and not 3 roots as the exercise says. Here's the 2 graphs : http://postimage.org/image/cltihi9kh/ http://postimage.org/image/gsn4sg97f/ Am i wrong ? Do both have only 3 roots in [0,3] and [-2,2] ?

  1. Concerning the Newton's method , how am i supposed to check out which roots have quadratic congruence and which not???

  2. Accuracy means tolerance e=10^(-6), right ?

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