## 18.014 Final Comments and Grades |
---|

Lemma: You can check that if p(x) is a polynomial with rational coefficients, then

Note that 1+x+x^2 + ... = 1/(1-x); this converges for x=1/2 (or indeed for any x between -1 and 1). Show that if you apply x d/dx to 1/(1-x) 100 times, and plug in x=1/2, you get the desired sum, and (using the lemma) that this is rational.

(That is the kernel of the solution; if you'd like to hear more details, just ask!)

(Congratulations to Russell Moriarty for solving this very hard problem!)

Code | Quiz 4 grade | Overall grade |

1024 | 96 | A+ |

3837701826 | 57 | C+ |

4410849 | 58 | B+ |

5NGK | 82 | A |

9666703 | 78 | A |

A27L | 55 | C+ |

A985586 | 58 | A- |

ABC123 | 84 | A |

Blue32 | 59 | A- |

D007 | 71 | A- |

FU42 | 38 | C- |

gr8score | 35 | C- |

GS57 | 61 | A- |

JAC | 79 | A |

joondol | 65 | A- |

kermit | 28 | C- |

oltugaykut | 94 | A+ |

rax65537 | 64 | C- |

S21 | 85 | A+ |

SPX0873 | 94 | A |

Back to the 18.014 webpage.