%\showframe \setuppapersize[S6][S6] \setuplayout [width=middle, top=1cm, bottom=1cm, backspace=1cm, leftmargin=0pt, rightmargin=0pt, footer=0pt, header=0pt] \setuppagenumbering [state=stop] \setupwhitespace[medium] \setupindenting[medium] \setupbodyfont[lbr,14pt] \setupcolors[state=start] \definecolor[darkred][r=0.5, g=0.0, b=0.0] \definecolor[darkgreen][r=0.0, g=0.5, b=0.0] \setuphead [subject][color=blue] \starttext \startstandardmakeup \startcolor[darkred] \startalignment[center] \tfd Using Technology \blank \tfd in\blank \tfd Teaching Multivariable Calculus\vfill \tfb David Arnold\vfill \tfb Humboldt Mathematics Colloquium\blank \tfb\currentdate[month,year] \stopalignment \stopstandardmakeup \subject{Matlab} In order to use Matlab effectively, students must understand that Matlab's basic data structure is the matrix. \startitemize \item Entries in rows are separated by commas. \starttyping >> u=[1,2,3] u = 1 2 3 \stoptyping \item Rows are terminated by semicolons. \starttyping >> v=[1;2;3] v = 1 2 3 \stoptyping \item Row entries can also be separated by spaces. \starttyping >> A=[1 2;3 4] A = 1 2 3 4 \stoptyping \stopitemize \page \subject{The Algebra of Vectors} \startitemize \item Vectors are added element by element. \starttyping >> u=[1,2,3]; v=[4,5,6]; >> u+v ans = 5 7 9 \stoptyping \item Vectors are subtracted element by element. \starttyping >> u=[1;2;3]; v=[4;5;6]; >> u-v ans = -3 -3 -3 \stoptyping \item Scalar multiplication is performed on each element. \starttyping >> u=[7,8,9]; >> 2*u ans = 14 16 18 \stoptyping \stopitemize \page \subject{Matrices} \startitemize \item Matrices of equal size are added (or subtracted) element by element. \starttyping >> A=[1,2,3;4,5,6]; B=[1,1,1;2,2,2]; >> A+B ans = 2 3 4 6 7 8 \stoptyping \item Scalar multiplication is performed on each entry. \starttyping >> A=[1,2;3,4;5,6;7,8]; >> 2*A ans = 2 4 6 8 10 12 14 16 \stoptyping \stopitemize \page \subject{Unorthodox} Subtracting a scalar from a matrix or vector makes no sense mathematically. \startformula \left(\matrix{1 & 2 & 3\cr 4 & 5 & 6}\right)-1 \stopformula However, this is such a common occurrence, Matlab interprets this to mean \startformula \left(\matrix{1 & 2 & 3\cr 4 & 5 & 6}\right)-1=\left(\matrix{0 & 1 & 2\cr 3 & 4 & 5}\right). \stopformula \page \subject {Parametric Equations} \stoptext