TITLE: How to use AND condition in Desmos
QUESTION [7 upvotes]: Sorry maybe it's not typical mathematics question, but Desmos is very helpful in solving and testing mathematics issues, so maybe anyone could help me.
I can't figure it out how to use AND condition in Desmos
For example to make OR you can just use "comma", like that:
$ y=\{ A<0 \ \ \ \ , \ \ \ \ B>1 :\  f_1(x), \ \ \ \  f_2(x) \} $
But how to make AND? I mean something like that:
$ y=\{ A<0 \ \ \ \ AND \ \ \ \ B>1 : \ f_1(x), \ \ \ \ f_2(x) \} $
But that just doesn't work.
For any help thanks in advance.

REPLY [7 votes]: I haven't found a built-in conjunction function, so you might find helpful my workaround:
For simple domain restrictions, you can use a product of conditions:
$$y=f(x)\{\text{cond1}\}\{\text{cond2}\}\{\text{cond3}\}$$
$$y=(x^2-x)\left\{x^2>1\right\}\left\{x^4<3\right\}$$
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For complex piecewise functions, you can use this hack:
$$\text{cond1} = \left(\{\text{subcond1}:1,0\}\{\text{subcond2:1,0}\}\{\text{subcond3:1,0}\}=1\right)$$
$$
y=\left\{\\\color{red}{\left\{x^2>1:1,0\right\}\left\{x^4<3:1,0\right\}=1:\left(x^2-x\right)},\\\color{blue}{\left\{x^2>1.8:1,0\right\}\left\{x^4+x^2<25:1,0\right\}=1:x},\\\color{green}{-1}\right\}$$
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