👉 In mathematics, a subinterval of a continuous function is an interval that contains one point outside the original function's domain but includes all other points. For example, if \(f(x) = x^2\) and we want to find the subintervals of \(x > 0\), then the intervals are \((0,1)\), \((1,\infty)\), \((-1,0)\), \(\left(-\infty,0\right]\).