Possible Duplicate:
General::ivar is not a valid variable when plotting - what actually causes this and how to avoid it?
Beginner question:
Why can't I use D[]
like that?
Plot[{Sin[x], D[Sin[x], x]}, {x, -2 Pi, 2 Pi}]
If I assign the result of D[]
to a variable and put that variable in the list it works.
Plot[{Sin[x], Sin'[x]}, {x, -2 Pi, 2 Pi}]
? For any function of typef[x]
you can usef'[x]
in place of theD[f[x],x]
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