# Projection on the xy–plane of the curve of intersection of both surfaces [duplicate]

I am trying to make a projection on the xy-plane of the intersection of the surfaces from the functions: 1 + x^2 - y^2, 3 Log[1 + x^2].

Thanks.

• Please post copyable code so that users can easily play with it. – Henrik Schumacher Apr 22 '18 at 22:01
• @HenrikSchumacher sorry this was my first time posting a question, I´ll do it in the next. – Damian Muciño Apr 23 '18 at 17:23
• Mkay... I'll let you off with that... - this time. ;) – Henrik Schumacher Apr 23 '18 at 17:25

Using geometric region functions:

RegionPlot@
ImplicitRegion[
1 + x^2 - y^2 == 3 Log[1 + x^2],
{{x, -1.5, 1.5}, {y, -1.5, 1.5}}
]


See also: Plotting implicitly-defined space curves for other interesting approaches.

• What do you think about closing this topic as a duplicate of mathematica.stackexchange.com/q/34668/5478 and moving your answer there for completeness? – Kuba Apr 23 '18 at 8:48
• @Kuba I agree, your suggestion sounds reasonable to me. – MarcoB Apr 23 '18 at 14:09
• kuba @MarcoB seems like a good idea, I´ll do it. – Damian Muciño Apr 23 '18 at 17:27
ContourPlot[1+x^2-y^2==3Log[1+x^2],{x,-1.5,1.5},{y,-1.5,1.5}]