MCS 471 Homework 1: Nonlinear Equations


(Revised 2/07/96)

NOT Due: Practice Problems ONLY! (revised 2/07/96)



Bckground Reading: Gerald and Wheatley, Chapter 1

Topics
  1. Bisection Method
  2. Secant Method
  3. Newton's Method
  4. Fixed Point Interation
  5. Muller's Method
  6. Golden Section Search (See Lecture Notes, Not in Text)

Homework Problems:

In problems 1-7, use "EXAM PRECISION": Chop to 4 significant (4C) digits only when you write an intermediate or final answer down and continue calculations with those numbers recorded.
  1. Using the method of BISECTION starting with A(1)=1. and B(1)=2., find the root of F(X)=EXP(X)-3.5/X Record your answer in a table of K,A(K),B(K),F(A(K)),F(B(K)) for each iteration on (A(K),B(K)) for K=1 to 3. Compare your answer to that using fsolve of Maple.
  2. Find the root of F(X)=EXP(X)-3.5/X using the SECANT METHOD for 2 iterations beyond the starting guesses, X(1)=1. and X(2)=2. Record your answers in a table of K,X(K),X(K-1),F(X(K)),F(X(K-1)) for each iteration K. Compare your answer to the Bisection and Maple answers from the first question.
  3. Find the root of F(X)=EXP(X)-3.5/X on [1.,2.] using NEWTON'S METHOD until ABS(X(K)-X(K-1))<.5E-1. Record Results in table of K,X(K),F(X(K)). Use X(1)=1.5 to start. Compare your answer to the Bisection, Secant and Maple answers from the first and second questions.
  4. Find the root of F(X)=EXP(X)-3.5/X on [1.,2.] using MULLER'S METHOD until ABS(X(K)-X(K-1))<.5E-1. Record Results in table of K,X(K),F(X(K)). Use {1,2,1.5} as starting values. Compare your answer to the Bisection, Secant, Newton and Maple answers from the first through third questions.
  5. Numerically solve F(X)=LN(X)-1/X=0 by forming a convergent, fixed point iteration, other than Newton's, starting from X(1)=EXP(1). Record your answers in a table of K, X(K), for K= 1 to 3. Compare your answer to that using fsolve of Maple. Use the plot function of Maple to plot the problem function G(X).
  6. Find the minimum of G(X)=EXP(X)+7.8/X on (1,2) by the method of GOLDEN SECTION SEARCH for K=1,2,3 iterations. Display your answer in a table of K, AK, BK, XK, UK, GXK, GUX. Use Maple's plot to plot the function G(X) and compare your problem answer to that using minimize of Maple.
  7. Find the maximum and its location for G(X)=X*COS(X) on (0.4,1.4) by the method of GOLDEN SECTION SEARCH. Summarize your results by a tabulation of K, AK, BK, XK, UK, GXK, GUK for K=1 to 3. {WARNING!: Ignore the Maple part of this exercise since "maximize" obviously does not work for this simple trigonometric function. "Maximize" seems to work primarily for polynomial functions over algebraic fields (revised 2/07/96). However, it may work if you approximate "X*cos(x)" by the first few terms of its Taylor series. Use Maple's plot to plot the function G(X) and compare your problem answer to that using maximize of Maple.}
  8. Using Maple, get all the roots, including double and triple roots, of the polynomial

    x^5-11x^4+46x^3-90x^2+81x-27.

    Also plot the polynomial using the plot function of Maple, on [0,4].


    Web Source: http://www.math.uic.edu/~hanson/M471/mcs471hw1.html

    Click Here For Class HomePage