# What is wrong with my following vector plot

I am trying to plot the following:

VectorPlot[{Abs[
D[((-3 Cos[Sin[t]])/(Sqrt[
9 Cos^2[Sin[t]] + 4 Sin^2[Sin[t]]]))/(Sqrt[
9 Cos[Sin[t]]^2 + 4 Sin^2 [Sin[t]]]), t]],
Abs[D[((2 Sin[Sin[t]])/(Sqrt[
9 Cos^2[Sin[t]] + 4 Sin^2[Sin[t]]]))/(Sqrt[
9 Cos^2[Sin[t]] + 4 Sin^2[Sin[t]]]), t]]}, {t, -10, 10}]


I get this error:

Any suggestions as to where I am going wrong? It is probably something ridiculously simple, and if that is the case I apologize. Just really a beginner trying to figure this programming out.

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– user9660
Feb 27 '15 at 4:35

One syntax problem is Cos^2[Sin[t]] this should be Cos[Sin[t]]^2 (probably). Next, it doesn't look like VectorPlot is the right plotting function because you've only got one variable t. Assuming these guesses are right, you can plot:

Plot[Evaluate[{Abs[
D[((-3 Cos[Sin[t]])/(Sqrt[
9 Cos[Sin[t]]^2 + 4 Sin[Sin[t]]^2]))/(Sqrt[
9 Cos[Sin[t]]^2 + 4 Sin[Sin[t]]^2]), t]],
Abs[D[((2 Sin[Sin[t]])/(Sqrt[
9 Cos[Sin[t]]^2 + 4 Sin[Sin[t]]^2]))/(Sqrt[
9 Cos[Sin[t]]^2 + 4 Sin[Sin[t]]^2]), t]]}], {t, -10, 10}]


Or perhaps what you were looking for was ParametricPlot (Just replace Plot).