Integrate two function in R

Alaios <alaios <at> yahoo.com> writes:

Hello I have two function in R
like
g(x)=2x-3
and s(x)=5x^2+2

and I want to find the integrafl of the g(x)*s(x) inside the interval of [a,b]

?Analytically or numerically?
?It sounds like you want the answer analytically, in which case R
can't do it, but it is an easy integral

?g(x)*s(x) = 10*x^3-15*x^2+4*x-6
?indefinite integral = 10/3*x^4 -15/3*x^3 + 4/2*x^2 - 6*x + C
?evaluate between a and b

?or if you can't do this (although this is a very basic integral)
you can try it on Wolfram alpha/the Mathematica integrator (google
for it)

?use ?integrate (surprisingly enough) for 1-D numerical integration