Question

Question4 The six lines below from MATLAB script contain coding mistakes that will cause errors. P and explain those mistakes and propose corrections. 2.5 Marks Answer: x [-12-3 7]: % this line is correct! x(-3) 3; Plot(x): 96 uestion 5 2.5 Marks Give the display result in the command window for each command MATLAB Commands Displayed results 1 y xsqrt(-1); 2 x- roots([1 1 -6]) 3 a poly(12 -3) 4 Cl1 1-6 polyval(c, 1)

Answer 1

question 4

x=[-1 2 -3 7]%this line is correct
%x(-3)=3; This line is wrong. x(-3) is wrong. Subscript must be an integer.
x(3)=3;
%z=x*x //This line is wrong. For element by element multiplication, .* must be used.
z=x.*x;
%plot(x) //This line is wrong. For discrete time vector, stem is the plot command line path
stem(x);

Command window:

x =

-1 2 -3 7

x =

-1 2 3 7

z =

1 4 9 49

Question 5

x=-i; %i=sqrt(-1)
y=x*sqrt(-1); %(-i)*(i)=-((i)^2)=-(-1)=1
x+y %-i+1=1-i