# Manipulate shows an empty plot [closed]

My Manipulate expression

Manipulate[
Plot[100[x]^2/(T^4 (Exp[x/T] + 1)), {x, 0, 30}],
{T, 1, 4}]


shows an empty plot. How can I fix it?

## closed as off-topic by Michael E2, corey979, m_goldberg, Carl Lange, Mr.Wizard♦Apr 14 at 23:26

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question arises due to a simple mistake such as a trivial syntax error, incorrect capitalization, spelling mistake, or other typographical error and is unlikely to help any future visitors, or else it is easily found in the documentation." – Michael E2, corey979, m_goldberg, Carl Lange, Mr.Wizard
If this question can be reworded to fit the rules in the help center, please edit the question.

• 100[x]^2 is not proper syntax. Probably want 100(x)^2. Brackets [] denote function calls – Michael E2 Apr 14 at 16:44
• Actually no bracketing around x is needed: 100 x^2/(T^4 (Exp[x/T] + 1)) works fine. – m_goldberg Apr 14 at 19:42

f[x_, t_] := (100*x^2)/(t^(4) *(Exp[x/t] + 1))