Originally Posted by
aquaglass88 Hi I am trying to find use the definition of the definite integral to prove that
the integral of (x^2)dx in [a,b] = [(b^3) - (a^3)]/3
I started out using the Reiman Sums except I ended up with
lim as n approaches infinity [nab^2 - bab^2 + b^3 - na^3 + a^3 - ab^2]^2
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n^2
I have no clue how that equals b cubed minus a cubed over 3 and I'm not sure what I did wrong if I did.
THanks so much for your help!!