1.
Program displays 2^N.

2.
Prompt N
0 --> S
For(K, 1, N)
    Prompt A
    S+A --> S
End
Disp S/N

3.
ClDrw
FnOff
Prompt P0
Prompt K
DrawF P0*e^(K*x)

4.
ClDrw
FnOff
Prompt N
For (K, 1, N)
    Prompt P0
    Prompt C
    DrawF P0*e^(C*x)
End