Answer:
D. 5 +6k/n
Step-by-step explanation:
The width of the interval is (5 -2) = 3. The width of one of n parts of it will be ...
3/n
Then the difference between the left end point of the interval and the value of x at the right end of the k-th rectangle will be ...
k·(3/n) = 3k/n
So, the value of x at that point is that difference added to the interval's left end:
2 + 3k/n
The value of the function for this value of x is ...
f(2 +3k/n) = 2(2 +3k/n) +1 = (4 +6k/n) +1
= 5 +6k/n
