I also want that the user just enters numbers.
clear all;
close all;
x= -10:1:10;
A=input('Enter the A value ');
if A == 0
disp(' A is = 0');
end
B=input('Enter the B value ');
C=input('Enter the c value ');
y= (-B + sqrt(B.^2 -4*A*C))/2*A;
plot(x,y,'-r');
hold on
x1=-10:1:10;
y1= (-B - sqrt(B.^2 -4*A*C))/2*A;
plot(x1,y1);