Pratap-Page no.198,Ex.no.3)

code_begins

sage: y,z=var('y,z')
sage: plot3d((-5/(1+x**2+y**2)),(x,-3,3),(y,-3,3))

code_ends

Solution by:
- < VINAY >, < STUDENT .>, < Symbiosis,Pune >
- <Your Name>, <Profession>, <Organization>