# Plot derivative of integral with changing limits [duplicate]

My code is: Plot[D[Integrate[E^(t*(-x^2)),{x,t+2,t^2}],t],{t,-2,3}].

The errors/warnings are:

General::ivar: "-1.9999 is not a valid variable."

General::ivar: "-1.89786 is not a valid variable."

General::ivar: "-1.79582 is not a valid variable."

General::stop: "Further output of \!$$\* StyleBox[ RowBox[{\"General\", \"::\", \"ivar\"}], \"MessageName\"]$$ will be suppressed during this calculation. "

The graph turns out empty in the end.

What did I do wrong this time?

• Use Evaluated->True in Plot. – Spawn1701D Apr 28 '13 at 18:54
• That worked... Thanks. What does it try to do if I DON'T add this property? – user76568 Apr 28 '13 at 18:56
• If you check Plot's Attributes you will see that has the HoldAll attribute, hence the expression will remain unevaluated. – Spawn1701D Apr 28 '13 at 18:56
• Yes, or Plot[Evaluate@D[Integrate[E^(t*(-x^2)),{x,t+2,t^2}],t],{t,-2,3}]. I'm sure this is a duplicate question, but too lazy to look now:) – Ajasja Apr 28 '13 at 18:56
• It's a duplicate of this question, which a duplicate of another question. – Michael E2 Apr 28 '13 at 21:23