The definition of definite integral Who can explain exactly what is definite integral Not too much
The definition of definite integral: let the function of one variable y = f (x), which is defined in the interval (a, b). Divide the interval (a, b) into n small areas (a, x0) (x0, x1) (x1, x2). (Xi, b). Let △ xi = xi-x (i-1), take any point on the curve in the interval △ Xi as f (ξ I), make the sum formula: if λ is these small areas