So let's say f[x_, y_] := (2 x + 2 y + 1)^2, when I type Coefficient[f[x, y], x y] I receive 8. But what can I input to receive 1, when (x^0) (y^0)? Thanks!
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1 Answer
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Pardon me if I misunderstand your request.
{0, 0} /. CoefficientRules[f[x, y], {x, y}]
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Fold[Coefficient[##, 0] &, f[x, y], {x, y}]
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CoefficientList[f[x, y], {x, y}][[1, 1]]
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Or far more elegantly in this case as J.M. recommends in a comment:
f[0, 0]
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answered May 21, 2015 at 19:48
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2$\begingroup$ In fact, since it's a polynomial, even the humble
f[0, 0]works nicely. $\endgroup$ May 21, 2015 at 19:58 -
$\begingroup$ You're right, I don't know why I never thought about that $\endgroup$– MathewMay 21, 2015 at 20:00
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$\begingroup$ Not too late to edit, Wiz. ;) $\endgroup$ May 21, 2015 at 21:13
CoefficientArrays[]. $\endgroup$