问题及解答

>> printSeries((-1)^n*(n+1)/(3^n),n,0,10)
1,-0.66666667,0.33333333,-0.14814815,0.06172840,-0.02469136,0.00960219,-0.00365798,0.00137174,-0.00050805,0.00018629,

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>> :mode fraction
Switch into fraction calculating mode.
e.g., 1/2+1/3 will return 5/6

>> printSeries((-1)^n*(n+1)/(3^n),n,0,10)
1,-2|3,3*^2|9,-4*^3|27,5*^4|81,-6*^5|243,7*^6|729,-8*^7|2187,9*^8|6561,-10*^9|19683,11*^10|59049,

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