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MATH 241
MATLAB Problem Set 1
Print out the plots of each part of the following problems to hand. If you wish
to economize on the amount of paper, you may use the command subplot (page
93 of the MATLAB Companion).
The first four problems can be done on the command line, although it is useful
to put all the commands in an Mfile.
1. a) Use the command plot to draw the polygonal line in R2through the points
(1,2),(1.5,3),(2,2),(π, 4).
b) Draw the rectangle with vertices (1,1),(4,1),(4,3),(1,3). Be sure to close
the rectangle by drawing the fourth side. To make the drawn rectangle sit inside
a larger rectangle, we set the limits of the xand yaxes with the command
>> axis([0, 5, 0,4]).
2. Graph the function
f(x) = cos x
1 + x2
on the interval [0,2π].
a) Use the commands
>> x = linspace(0, 2*pi, 11);
>> y = cos(x)./(1+x.^2);
>> plot(x,y)
The result should be a polygonal line through the 11 points (xj, f(xj)), where
xj= (2πj)/10, j = 0,1,...,10.
b) Do this in a different way with the commands
>> f = inline(’cos(x)./(1+x.^2)’)
>> plot(x,f(x))
c) To make a smoother curve, increase the number of points.
>> x = linspace(0, 2*pi, 21);
>> plot(x,f(x))
>> x = linspace(0, 2*pi, 51);
>> plot(x,f(x))
3. a) Draw the circle with center at (1,2) and radius r= 3/2 with commands
