Graph the functions f(x) over the given interval. Partition the interval into 4 subintervals of equal length. Then add to your sketch the rectangles associated with the Riemann sum ∑ₖ₌₁ f(ck)Δxk, using the indicated point in the kth subinterval for ck.

a. f(x)=2x+4, [0, 2], left-hand endpoint.