diff2c1.m

Micro Electronic Device Fundermental

format short
%syms x
%plot(x,y1),grid
%plot(x,y1,x,g1),grid
%h=((48*0.5e-4)/135)^(1/4)
h=0.02
x=2:h:2.12
y1=(1/24)*x.^6-(13/8)*x.^2
g2=5/4*x.^4-13/4
m2=(1/(h^2))*(((1/24)*(x+h).^6-(13/8)*(x+h).^2)-2*((1/24)*x.^6-(13/8)*x.^2)+((1/24)*(x-h).^6-(13/8)*(x-h).^2))
det2=abs(g2-m2)
j=length(x);
fprintf('------------------------------------------------------------\n')
fprintf('  x               g2               m2                det2\n');
fprintf('------------------------------------------------------------\n')
for ii=1:j,
    fprintf('%-10.4f       %-10.4f      %-10.4f      %-10.4e\n',x(ii),g2(ii),m2(ii),det2(ii));
end
plot(x,y1,x,m2),grid