Yes or No? 1. Definite integral | f()dt exists, when the function f is differentiable over the interval [1, x]. 2. As long as it is continuous, and bounded over the interval of interest, a definite integral exists.. 3. Riemann sum approach is applicable only when the function is positive. 10 1 4. A Riemann sum can estimate -1 - dx . X 5. when x is a variable, | f()d is a function of x (x is not a fixed constant)