chứng minh:1/3+1/16+1/19+1/21+1/61+1/72+1/83+1/94<3/5
chứng minh:1/3+1/16+1/19+1/21+1/61+1/72+1/83+1/94<3/5
chung minh D=1/3+1/16+1/19+1/21+1/61+1/72+1/83+1/94< 3/5
Cho A=1/3 + 1/16 + 1/19 + 1/21 + 1/61 + 1/72 + 1/83 + 1/94
So sánh A với 3/5.
Cho A= 1/3+1/16+1/19+1/21+1/61+1/72+1/83+1/94
So sánh A với 3/5
Cho B=1/3+1/16+1/19+1/21+1/61+1/72+1/83+1/94
So sánh B với 3/5
B=1/3+1/16+1/19+1/21+1/61+1/72+1/83+1/94
So sánh B với 3/5 nêu cách giải nhé
Cho P= \(\frac{1}{3}+\frac{1}{16}+\frac{1}{19}+\frac{1}{21}+\frac{1}{61}+\frac{1}{72}+\frac{1}{83}+\frac{1}{94}\)
So sánh P với \(\frac{3}{5}\)
P = 1/3 + 1/16 + 1/19 + 1/21 + 1/61 + 1/72 + 1/83 + 1/94
P = 0, 5490527821
3/5 = 0, 6
Mà 0, 5490527821 < 0, 6
Nên: P < 3/5
Bài 3
Cho B =\(\frac{1}{3}+\frac{1}{16}+\frac{1}{19}+\frac{1}{21}+\frac{1}{61}+\frac{1}{72}+\frac{1}{83}+\frac{1}{94}\)
So sánh B=\(\frac{3}{5}\)
Ta có : 1/61 +1/72 +1/83 +1/94 < 1/60 x4 =1/15
1/16 +1/19 +1/21 < 1/15 x3 =3/15
1/3 =5/15
Do đó: B < 1/15 + 3/15 +5/15 = 9/15= 3/5
Vậy B< 3/5
\(\text{Bài giải}\)
\(\text{Ta có : }\)
\(B=\frac{1}{3}+\frac{1}{16}+\frac{1}{19}+\frac{1}{21}+\frac{1}{61}+\frac{1}{72}+\frac{1}{83}+\frac{1}{94}\)
B = 0,333333333 + 0,0625 + 0,0526315789 + 0,0476190476 + 0,0163934426 + 0,0138888889 + 0,0120481928 + 0,0106382979
B = 0,549052782
Cho B=\(\frac{1}{3}+\frac{1}{16}+\frac{1}{19}+\frac{1}{21}+\frac{1}{61}+\frac{1}{72}+\frac{1}{83}+\frac{1}{94}\)
So sánh B với \(\frac{3}{5}\)