Texas Instruments TI-84 Plus Silver Edition Manual page 54

To calculate a Riemann Sum using left endpoints, follow these instructions:
Enter the function at Y= as Y1 .
Enter the number or rectangles (n) as N, so press n, STO>, ALPHA, N .
Enter the left endpoint of the interval (a) as A, so press a, STO>, ALPHA, A.
∆ and store it as W . Press the number, then STO> ALPHA W .
Compute x
Press Y= and enter the following commands as Y5 : sum(seq(Y1(A + K*W)*W, K, 0, N-1)
Press VARS, Y-VARS, Function, 5, ENTER.
Example: Use a Riemann Sum to approximate the area under
rectangles and left endpoints on the interval [1, 6].
Enter f x as Y1 on ( )
the Y= menu.
∆ .
Compute x
Result. Choose sum(.
F F F F inding a Riemann Sum inding a Riemann Sum
inding a Riemann Sum inding a Riemann Sum
15 STO> ALPHA N
ANS STO> W
Go to Y= and arrow down to Y5 .
nd
Result. Press 2 STAT and Result. Press seq( .
choose OPS.
- 54 -
1
= + using 15
2
f x ( ) x 3
2
1 STO> ALPHA A
nd
2 STAT (choose MATH ).