One point quadrature rule with cardinal B-spline

To compute approximately an integralequation(1)∫0mφm(x)f(x)dx, where φm(⋅)φm(⋅) is cardinal B-spline, we used composite rectangular rule. We proved that, on the “quasi uniform” mesh, the used formula has, conditionally speaking, algebraic degree of exactness m−1m−1. Under additional assumptions, algebraic degree of exactness is m.