Dsolve.. The Function appears with no argument..

Questions
1

DSolve[{k’[ t ] == k^3*t^2, k[1] == 3}, k[ t ], t]
and I get the error
DSolve::dvnoarg: The function k appears with no arguments. >>

I’ve tried clearing and using only one =, but neither seems to work. What’s the problem?
Edit: there are no spaces in the brackets in the actual code, just put those in because they wouldn’t show otherwise.
ty

2

Somewhere in the input there is a ‘k’ which should be ‘k[ t ]’, in other words the function k appears without an argument.

3

Ah the k[ t ] ^3 also needed [ t ] .. didn’t think so.
Problem resolved.
Thanks.

4

(1/T)(-Co + DCsT - Cp D ((Log (1 + R - t1)^2)/(1 + R - T) + t1) -
Cd D (-T + (Log (1 + R - t1)^2)/(1 + R - T) + t1) -
Ch (-((D t1^2)/2) + D t1 ((Log (1 + R - t1)^2)/(1 + R - T) + t1) +
D (1 + R) (-Log (1 + R - T) T + Log (1 + R - t1) t1 +
1/2 (T + 3 t1) + (
Log (1 + R - t1) (1/2 (-1 - R) - T + t1 - 3/2 (R + t1^2)))/(
1 + R - T))))

Differentiate with respect to T

17.1.23.nb (23.2 KB)

5

The argument of Log, and of all the functions in WL, must be within square braces [], not parentheses ().