# Math Help - Riemann Sums and Integrals

1. ## Riemann Sums and Integrals

Question: Find the integral of the equation 2x+1 from 0 to 3 using Riemann Sums.

Please show me how to do this, I keep on getting 9 as the answer, but it is actually 12.

2. It depends on the Riemann Sum that you use. Either right, left or center. Also it depends on how many intervals you split it up into. Are there anymore instructions to the problem?

3. I am using right Reimann sums and I am using infinite intervals n->∞.

4. Then that's the same as the actual integral if $n \Rightarrow \infty$. Cause that means that $dx \Rightarrow 0$.

So, take the actuall integral and you get:

$\int_0^3 2x + 1\, dx = x^2 + x$ between 0 and 3.

$= 3^2 + 3 - (0^2 + 0)$

5. ok thnks!