VPA error Index exceeds number of array elements

my VPA solve was working fine and then after running twice, I suddenly have an "Index exceeds number of array elements (1)"

This is what I am running, and its extremely simple. I dont know why it would stop working after functioning prior.

syms t

P(t)= 30/(3+7*exp((-.03*t)))

P(1960)

vpa(P(1960))

Answer 1

[the cyclist]

I'm confused, because the code you posted runs fine:

syms t
P(t)= 30/(3+7*exp((-.03*t)))

P(t) = 

P(1960)

ans = 

vpa(P(1960))

ans = 

9.9999999999999999999999993216384

Is it possible that somewhere in between you defined P as a variable, and then tried to access?

P = 7;
vpa(P(1960))

Index exceeds the number of array elements (1).

[Dick Marruffo]

That's my issue. I didnt Change anything in my code, I just pressed the run button to ensure my formula was running and I got an error with no change. and I have double checked that P is not a variable