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(10 points)

  1. Let $f(x)$ be twice continuously differentiable on $\Re^n$.
    1. Define local and global minimum for $f(x)$.
    2. Define Newton's method for minimization of $f(x)$.
  2. Show that the function $f(x)$ defined on $\Re^1$ by

    \begin{displaymath}f(x)=x^{\frac 43}
\end{displaymath}

    has a unique global minimizer at $x^*$ but that, for any nonzero initial point $x^{(0)}$, the Newton's Method sequence $\left\{x^{(k)}\right\}$ with initial point $x^{(0)}$ for minimizing $f(x)$ diverges.



Henry Wolkowicz
2001-02-28