> t2:= x -> cos(x);

> it2:= x -> arccos(x);

> v1:= plot(t2(x), x = 0..Pi, thickness=2, color = black):

> v2:= plot(it2(x), x = -1..1, thickness=2, color = red):

> v3:= plot(x, x = 0..Pi, thickness=2, color = blue):

> v4:= textplot([1.6,.6,`cos(x)`], thickness=2, color = magenta):

> v5:= textplot([2,1.6,`y=x`], thickness=2, color = magenta):

> v6:= textplot([.7,1.7,`arcos(x)`], thickness=2, color = magenta):

> display({v1,v2,v3,v4,v5,v6});