1.
0 --> S
For(K, 1, 100)
    S + K --> S
End
Disp S

2.
Prompt A
Prompt B
Prompt N
(B-A) / N --> DX
0 --> L
For (K, 0, N-1)
    L + y1(A + K*DX) * DX --> L
End
Disp "LEFT = ", L
0 --> R
For (K, 1, N)
    R + y1(A + K*DX) * DX --> R
End
Disp "RIGHT = ", R

OR

Prompt A
Prompt B
Prompt N
(B-A) / N --> DX
0 --> L
0 --> R
For (X, A, B - DX, DX)
    L + y1(X) * DX --> L
    R + y1(X + DX) * DX --> R
End
Disp "LEFT = ", L
Disp "RIGHT = ", R

3.
N=10:     LEFT = 56.385 and RIGHT = 69.885
N=100:     LEFT = 62.32635 and RIGHT = 63.67635
N=250:     LEFT = 62.730216 and RIGHT = 63.270216