How would I find the fractions needed for the right and left endpoints?

Question

Estimate the area under the graph of f(x) = 1/x² +3 over the interval [-1,2] using five approximating rectangles and Right endpoints. 

Rn= ----

Repeat the approximation using left endpoints.

Ln= ---

Answer 1

WHAT?? Does nobody care that f(x) = 1/x2 +3 is UNDEFINED for x=0.0, whether it is a right-side point or a left-side point?

Answer 2

Six divisions are needed to get 5 endpoints (draw and label a diagram!).

Distance from -1 to 2 is 3 units. 3 / 6 = 1/2.

The right sided points are -0.5, 0, 0.5, 1.5, and 2.0.

The left sided points are -1.0, -0.5, 0.0, 0.5, 1.0, and 1.5.