How to plot a line where the variable changes condition.

So from 0<x<1.8 Z=1.25*((0.72*(x/5))-((x/5).^2));

and from 1.8<x<5 Z=(1125/1024)*((0.28+(0.72*(x/5)))-((x/5).^2));

Is there anyway I can enter this without putting it into 2 different parts?

Thanks

Answer 1

[Matt J]

   Z=@(x) 1.25*((0.72*(x/5))-((x/5).^2)).*(x>0 & x<1.8)+...
           (1125/1024)*((0.28+(0.72*(x/5)))-((x/5).^2)).*(x>1.8 & x<5);

Answer 2

[bym]

c = [-.05 .18 0;...
     -.0439 .1582 .3076];
b = [0,1.8,5];

f = mkpp(b,c);
xx = 0:.1:5;
plot(xx,ppval(f,xx))