Theorem 2.8( Gauss-Legendre Two-Point Rule). If f is continuous on -1,1,the )d≈G2(f)=f()+f( 2.90) The Gauss-legendre rule G2(f) has degree of precision n=3. If fE C-1,1] the en f(x)dx≈G2)=f()+f(-5)+E2(f) (2.91) where E2(f) 135 (2.92)