Plot Error Equation Error Needs Fix

%if true
  % code
%end
x = linspace(-0.02,0.02);
y = -(2.56*10^10)*x;
plot(x,y)
title('\sigma_{xx}')

r=linspace(-0.02,0.02);
s=(2.56*10^6)-(6.4*10^9)*(r^2);
plot(r,s)
title('\sigma_{xy}')

I want to plot these two graphs but for the second graph, there is error for some reason

Answer 1

[KSSV]

Read about element by element operations.

x = linspace(-0.02,0.02);
y = -(2.56*10^10)*x;
plot(x,y)
title('\sigma_{xx}')

r=linspace(-0.02,0.02);
s=(2.56*10^6)-(6.4*10^9)*(r.^2);  % change here use .^ 
plot(r,s)
title('\sigma_{xy}')