How Do Mathematicians Say Hi?

With this equation, of course:

Graph that and you'll get this:

via Krulwich Wonders

See also: I Heart Math T-Shirt over at the NeatoShop

That is not an equation.

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Almost, guys - the issue is that your range was off (as Seban678 wrote, it's probably limitation with Wolfram Alpha):

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Try that input:
plot e^(-3*((0.5+x)^2+y^2/2))+e^(-x^2-y^2/2)*cos(4*x), x=-3..3, y=-5..5

I don't think it's possible to see the intersection at z=0.001 as they've done in the picture though.

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This is the WolframAlpha input:

e^(-3*((0.5+x)^2+y^2/2))+e^(-x^2-(y^2/2))*cos(4*x)

.. but it still doesn't say "Hi". I'm sad.

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The source page says "plot the following equation over the region -3<x<3, -5<y<5. It also suggested that you should only plot the z values in the range 0<z<0.001."

Is there a way to clip the 3D plot in Wolfram Alpha?

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I was going to post the same thing. Wolfram Alpha seems to disagree, that's not HI.

Neat link though. I already knew the batman one (previously featured at Neatorama, IIRC), and the origami mermaid is worth trying