Why function displays one result, and how to stop it?

Hello. I have made function that calculate roots of quadratic function ax^2 + bx +c, and then create graph for this function.

Also I have some text in function that will be printed to the screen. But also, except this text, function displays ans=(some number - first root).

I want just my text to be displayed. Here is the code:

function [x1, x2] = kvadratna(a, b, c)
D = b^2 - 4*a*c;
x = -10:0.2:10; %x osa za grafik
y = a.*x.^2 + b.*x + c; %funkcija
if(D<0)
    fprintf('Funkcija nema realne nule');
elseif(D==0)
    x1 = -b/(2*a);
    x2=x1;
    fprintf('Funkcija ima dvije iste realne nule\n');
    fprintf('Te realne nule su: %.2f i %.2f\n',x1,x2);
elseif(D>0)
    x1 = ((-b+sqrt(D)) / (2*a));
    x2 = ((-b-sqrt(D)) / (2*a));
    fprintf('Funkcija ima dvije razlicite realne nule\n');
    fprintf('Te realne nule su: %.2f i %.2f\n',x1,x2);
end

plot(x,y,'g')
grid on
xlabel('x')
ylabel('f(x)')
title('CRTANJE FUNKCIJE')
end

and here is what it displays:

I dont want this ans=-1 to be displayed. How can I fix this?

[Gani]

Run your function like this

[~, ~] = kvadratna(1, 6, 5)

or I can see you are directly printing the results and you dont want function output to be stored, then you can remove function outputs.

function kvadratna(a, b, c)
......
end 

[Faris Hajdarpasic]

Okay. You gave me 2 answers and thanks. But I just came up with another thought. What if I want a function to print both x1 and x2 without using any fprintf in function?

[Gani]

function [x1, x2] = kvadratna(a, b, c)
D = b^2 - 4*a*c;
x = -10:0.2:10; %x osa za grafik
y = a.*x.^2 + b.*x + c; %funkcija
if(D<0)
    fprintf('Funkcija nema realne nule');
elseif(D==0)
    x1 = -b/(2*a);
    x2=x1;
%     fprintf('Funkcija ima dvije iste realne nule\n');
%     fprintf('Te realne nule su: %.2f i %.2f\n',x1,x2);
elseif(D>0)
    x1 = ((-b+sqrt(D)) / (2*a));
    x2 = ((-b-sqrt(D)) / (2*a));
%     fprintf('Funkcija ima dvije razlicite realne nule\n');
%     fprintf('Te realne nule su: %.2f i %.2f\n',x1,x2);
end
plot(x,y,'g')
grid on
xlabel('x')
ylabel('f(x)')
title('CRTANJE FUNKCIJE')
end

[Faris Hajdarpasic]

Thanks!

Answer 1

[KSSV]

Call the function as below:

[x1,x2] = kvadratna(1, 6, 5) ;