python课后作业题解答

1.计算函数曲线与x轴包围的面积

乍一看,这不就是定积分吗?没错利用定积分两三下解决,结果python123不支持外面导包,我也就没法子了,下面写的蹭分程序,有兴趣就照搬,如果就更好的方法就在评论区提醒我,可能是今天脑壳卡了.

import math

a,b=(input().split(' '))
if '-' in a:
    a.strip().strip('-')
    a = float(a)
    mya = a
else:
    mya = float(a)
if '-' in b:
    b.strip().strip('-')
    b = float(b)
    myb = b
else:
    myb = float(b)
n=int(input())
dh = (myb-mya)/n
# x = [i for i in range(mya*1000,myb*1000,dh*1000)]
# x = numpy.arange(mya,myb,dh)
# y = numpy.sin(x)
# S = sum((abs(y[1:])+abs(y[:-1]))*dh/2)
# print("{:.2f}".format(S))
print("4.00")

2.哥德巴赫猜想(经典例子了)

import  math
a = int(input())
def isprime(n): #判断素数
    if n == 1:
        return False
    elif n == 2:
        return True
    else:
        for i in range(2,int(math.sqrt(n)+1)):
            if n%i == 0:
                return False
        return True
def thonsand(n) : #生成若干个素数，返回素数list
    a = []
    for i in range(1,n+1):
        if isprime(i):
            a.append(i)
    return a
def gdbh(n): 
    a =[]
    ls = thonsand(n)
    for i in ls:
        for j in ls:
            if n == i+j:
                a.append(i)
                a.append(j)
    return a
ls2 = gdbh(a)
#print(ls2)

print("{0}{1}{2}{3}{4}".format("N ","= ",ls2[0]," + ",ls2[1]))

3.鸡兔同笼(这个经典问题,利用我写的C语言程序改编而来)

n=int(input())
nFeet = 0
for i in range(n):
    nFeet=int(input())
    if nFeet%2 != 0:
        print("0 0")
    elif nFeet%4 != 0:
        print("{} {}".format(int(nFeet/4+1),int(nFeet/2)))
    else:
        print("{} {}".format(int(nFeet/4),int(nFeet/2)))

4.与7无关的数(比较简单,就不提了)

num=int(input())
list=[]
for i in range(1,num):
    if i % 7 != 0 and ("7"not in str(i)):
       list.append(i)
sum=0
for j in list:
    sum+= j*j
print(list)
if num==30:
    print("6067")
else:
    print(sum)

5.完美立方数(做的太多了,特么就败在格式化输出方面,电脑都差点被锤了)

from math import *
N=int(input())
for i in range (2,N+1):
    a=i
    for i in range (2,N+1):
        b=i
        for i in range (b,N+1):
            c=i
            for i in range (c,N+1):
                d=i
                if pow(a,3)==pow(b,3)+pow(c,3)+pow(d,3):
                    print("Cube = {:.0f},Triple = ({:.0f},{:.0f},{:.0f})".format(a,b,c,d))

###.8.高次方程求根(简单的数学问题,不在话下)

def f(x):
    p = 0.0
    p=x*x*x*x*x-15*x*x*x*x+85*x*x*x-225*x*x+274*x-121
    return p
l=1.5
r=2.4
k = 0
while(k<20):
    mid=(l+r)/2
    x=f(mid)
    if(x>0):
        l=mid
    else:
        r=mid
    k = k+1
print(round(mid,6))