MATLAB intro exercise

>> a=[1 2 -1 1 5/6 4.5]

a =

1.0000 2.0000 -1.0000 1.0000 0.8333 4.5000

>> a=[1 2 -1 1 5/6 4.5]; %qyadratic eqn coeffts with
>> b=[-1 -14 0 -6 -4 -12.15]

b =

-1.0000 -14.0000 0 -6.0000 -4.0000 -12.1500

>> c= [-2 24 -1 10 4.8 8.1]

c =

-2.0000 24.0000 -1.0000 10.0000 4.8000 8.1000

>> n= length(a)

n =

6

>> for m=1:n end solution for eqn 1

disc =

9

x1 =

2

x2 =

-1

solution for eqn 2

disc =

4

x1 =

4

x2 =

3

solution for eqn 3

disc =

-4

no real roots solution for eqn 4

disc =

-4

no real roots solution for eqn 5

disc =

0

x1 =

2.4000

x2 =

2.4000

solution for eqn 6

disc =

1.8225

x1 =

1.5000

x2 =

1.2000

>>
>> disc=zeros(1,n); x1=disc; x2=disc

x2 =

0 0 0 0 0 0

>> disc(m)

ans =

0

>> x1(m)

ans =

0

>> X=[1 3 -5 -1]';
>> A=[-2 1 00; 3 4 7 -2; 1 0 0 1; 6 7 -2 0; 5 3 1 0];
??? Error using ==> vertcat
CAT arguments dimensions are not consistent. >> A=[-2 1 0 0; 3 4 7 -2; 1 0 0 1; 6 7 -2 0; 5 3 1 0];
>> [m n]= size(A);
>> Y=zeroes(5,1);
??? Undefined function or method 'zeroes' for input arguments of type
'double'.

>> Y=zeros(5,1);
>> for k =1:m for l=1:n
Y(k)=Y(k)+A(k,l)*X(l);
end end >> Y

Y =

1 -18 0 37 9

>> disp('Expected answer is:')
Expected answer is:
>> Y1=A*X

Y1 =

1 -18 0 37 9

>> N=100;K=17;
>> n=N; found=0;
>> while found==0 if mod(n,K)==0 found=1; else n=n-1; end end >> help mod MOD Modulus after division. MOD(x,y) is x - n.*y where n = floor(x./y) if y ~= 0. If y is not an integer and the quotient x./y is within roundoff error of an integer, then n is that integer. The