%dm07202
%繪制實指數信號波形
syms  a  t 
f=sym('exp(a*t)')
f1=subs(f,'a','-0.5')
subplot(2,3,1)
ezplot(f1,[-3,3])
f2=subs(f,'a','0.5')
subplot(2,3,2)
ezplot(f2,[-3,3])
f3=subs(f,'a','0')
subplot(2,3,3)
ezplot(f3,[-3,3])
set(gcf,'color','w')