How do you sketch f(x,y)=arcsin(x^2+y^2-2)f(x,y)=arcsin(x2+y22)?

1 Answer
Feb 16, 2015

Hello !

Let S be the surface of equation z = \text{arcsin}(x^2+y^2-2)z=arcsin(x2+y22).

S is a surface of revolution because z = F(r)z=F(r) where r=sqrt{x^2+y^2}r=x2+y2. Here, F(r) = \text{arcsin}(r^2-2)F(r)=arcsin(r22).

First, you study the curve of equation z = \text{arcsin}(x^2-2)z=arcsin(x22) : you get

enter image source here

Second, you rotate this curve around (0z) axis and you get the surface S :

enter image source here

Remark that ff exists only on the domain defined by 1\leq x^2+y^2\leq 31x2+y23 : it's a disk of radius sqrt{3}3 with an circular hole of radius 1.