Why am I getting Nan as a result of the function?

Question

Java

Good afternoon!
Happy holidays everyone!
I write such a return in a function

return x = (double)Gdx.graphics.getWidth()/2+Math.sqrt((85*85)-(y+(double)Gdx.graphics.getHeight()/2)*(y+(double)Gdx.graphics.getHeight()/2));

In response I get Nan
I apologize for the stupid question, I just usually get stupid for a long time with this kind of error.
Chiadnt?

Answer 1

I think because (85*85) < (y+(double)Gdx.graphics.getHeight()/2)*(y+(double)Gdx.graphics.getHeight()/2
Which, in general, is logical, if it is the height of the screen.So the root of a negative number is a complex number, and Math.sqrt legitimately returns NaN.All further calculations with NaN return NaN.