Question

The function f(x)=2x+1 is defined over the interval [2, 5]. If the interval is divided into n equal parts, what is the value of the function at the right endpoint of the kth rectangle?

Answer 1

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