二项式定理通项演示

GeoGebra 命令及参数

1. Sequence(i + If[i ≟ 1, "st", If[i ≟ 2, "nd", If[i ≟ 3, "rd", "th"]]], i, 1, n + 1) → listterm
2. SelectedIndex(listterm) → termno
3. Text("=" + (Sum[Sequence[If[i ≟ r, "\textcolor{red}\underline{", ""] + "\binom{" + n + "}{" + (i) + "}" + a + "^" + "{" + (n - i) + "}" + b + "^" + "{" + (i) + "}" + (If[i ≟ r, "}", ""]) + (If[i < n, "+", ""]), i, 0, n, 1]]), A, false, true) → textlistexpandbinomline1
4. Text("=" + (Sum[Sequence[If[i ≟ r, "\textcolor{red}\underline{", ""] + (If[Binomial[n, i] ≟ 1, "", "" + (Binomial[n, i])]) + (If[n - i < 1, "", "" + a]) + "^" + "{" + (If[n - i < 2, "", "" + (n - i)]) + "}" + (If[i < 1, "", "" + b]) + "^" + "{" + (If[i < 2, "", "" + (i)]) + "}" + (If[i ≟ r, "}", ""]) + (If[i < n, "+", ""]), i, 0, n, 1]]), B, false, true) → textlistexpandbinomline2