Forgot the curly braces? Desmos will scream “invalid.” Slow down. Type y = x^2 {x < 0}, not y = x^2 x < 0—that’s gibberish.
Using the wrong bracket? It only accepts curly braces {}, not square brackets or parentheses. Square brackets are for angry math teachers. Curly braces are for friendly mathematicians.
Your graph is blank? You might have typed the interval backwards, like {x > 5} when you meant {x < 5}. Swap the inequality. Sometimes the simplest fix is the one you overlook while sipping cold coffee.
