Hello everybody I need to approximate the amount of integral by using legendre quadrature. I have written a program which doesn't give me a logical answer; Can anybody help me and send the correct program? For example the approximated amount of integral of ( x ^2) on (-1,1) based on legendre quad rule. integrand<-function(x){x^2} rules <- legendre.quadrature.rules( 50 ) order.rule <- rules[[50]] chebyshev.c.quadrature(integrand, order.rule, lower = -1, upper = 1) Thank you Diba [[alternative HTML version deleted]]