Chung minh rang: moi n thuoc z ( n khac 0,n khac -1) thi : Q =1\1.2+1\2.3+1\3.4+......+1\n(n+1) khong phai la so nguyen
cho phan so A = n - 5 / n+1 ( n thuoc Z , n khac -1)
a. Tim n de A toi gian
cho phan so A=n+1/n-3 (n thuoc z;n khac 3)
tim n de A co gia tri nguyen
cho A=n-5/n+1 n thuoc z va n khac -1
a, tim n deA co gia tri ngyen
b, tim n de A la phan so toi gian
minh can gap cac ban lam mau len!!!!!!!!!!!!!!!!!!!!!!!!!
Giup to bai nay voi : Chung minh voi n thuoc N sao phan so sau la phan so toi gian 4n+1/6n+1
cho bieu thuc A=3n+2/n+1(n thuoc Z;n khac -1. chung minh A la ps toi gian voi moi gia tri cua n
chung to phan so toi gian voi n thuoc n a , n+1/2n+3 b, 2n +3 /4n +8
Chung minh rang phan so sau toi gian voi moi n thuoc N 2n+1/2n(n+1)
n-5/n+1(n thuoc Z;n khac -1)
tim n de n-5/2+1 lon nhat