#35) p114 f(x)
f1(x)=(x+1)^2
f2(x)=2*x+1
f3(x)=(4-x)^2
f=piecewise([[(-2,0),f1],[(0,3),f2],[(3,6),f3]])
p1=plot(f,color='red')
#35 p114 f'(x)
f1(x)=2*x+2
f2(x)=2
f3(x)=2*x-8
f=piecewise([[(-2,0),f1],[(0,3),f2],[(3,6),f3]])
p2=plot(f,color='green')
p1+p2