Chứng tỏ:
\(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}.\frac{34}{2}....\frac{60}{2}=1.3.5....59\)
chứng tỏ: \(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}......\frac{60}{2}=1.3.5......59\)
\(1.3.5....59=\frac{\left(1.3.5....59\right).\left(2.4.6....60\right)}{2.4.6....60}=\frac{\left(1.2.3.4.5...30\right).31....59.60}{2^{30}.\left(1.2.3...30\right)}=\frac{31.32....60}{2^{30}}=\frac{31}{2}.\frac{32}{2}.\frac{33}{2}...\frac{60}{2}\)
Chị quản lý Sao làm tốt thế mà chẳng được olm công nhận nhỉ
Vì đó là người quản lí nên công nhận cũng có được gì !!!
Chứng tỏ rằng \(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}...\frac{60}{2}=1.3.5...59\)
Ta có: \(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}...\frac{60}{2}=\frac{31.32.33...60}{2.2.2...2}=\frac{31.32.33...60}{2^{30}}\)
(30 số 2)
\(=\frac{\left(31.32.33...60\right).\left(1.2.3...30\right)}{2^{30}.\left(1.2.3...30\right)}=\frac{31.32.33...60.1.2.3...30}{\left(2.1\right).\left(2.2\right).\left(2.3\right)...\left(2.30\right)}=\frac{\left(1.3.5...59\right).\left(2.4.6...60\right)}{\left(2.4.6...60\right)}=1.3.5...59\)
\(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}...\frac{60}{2}=\frac{31.32.33...60}{2^{30}}\)
\(=\frac{\left(31.32.33...60\right).\left(1.2.3...30\right)}{2^{30}.\left(1.2.3...30\right)}\)
\(=\frac{1.2.3...60}{2^{30}\left(1.2.3...30\right)}\)
\(=\frac{\left(1.3.5.7...59\right)\left(2.4.6.8...60\right)}{\left(2.4.6.8...60\right)}\)
\(=1.3.5.7...59\)
Chứng tỏ rằng:
\(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}...\frac{60}{2}=1.3.5...59\)
Ta có:
\(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}...\frac{60}{2}=\frac{31.32.33...60}{2^{30}}\)
\(=\frac{\left(31.32.33...60\right).\left(1.2.3...30\right)}{2^{30}.\left(1.2.3...30\right)}\)
\(=\frac{1.2.3...60}{2^{30}\left(1.2.3...30\right)}\)
\(=\frac{\left(1.3.5.7...59\right)\left(2.4.6.8...60\right)}{\left(2.4.6.8...60\right)}\)
\(=1.3.5.7...59\)
Vậy \(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}...\frac{60}{2}=1.3.5.7...59\)
Chứng tỏ rằng
\(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}...\frac{60}{2}=1.3.5...59\)
Chứng minh rằng \(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}.....\frac{60}{2}\)= 1.3.5...59
Chứng tỏ \(\frac{31}{2}.\frac{32}{2}...\frac{60}{2}=1.3.5...59\)
Ta có: \(\frac{31}{2}.\frac{32}{2}...\frac{60}{2}=\frac{31.32...60}{2^{30}}=31.33...57.59.\left(\frac{32.34...58.60}{2^{30}}\right)\)
\(=31.33...57.59.\left(\frac{16.17...29.30}{2^{15}}\right)=17.19...27.29.31.33...57.59.\left(\frac{16.18...30}{2^{15}}\right)\)
\(=17.19...57.59.\left(\frac{8.9...15}{2^7}\right)=9.11.13.15.17...57.59.\left(\frac{8.10.12.14}{2^7}\right)\)
\(=9.11...57.59.\left(\frac{4.5.6.7}{2^3}\right)=5.7.9...57.59.\left(\frac{4.6}{2^3}\right)\)
\(=5.7.9...57.59.3=1.3.5...59\)
CMR: \(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}.....\frac{60}{2}=1.3.5.....59\)
\(\frac{31}{2}\)\(.\)\(\frac{32}{2}\)\(.\)\(\frac{33}{2}\)\(....\)\(\frac{60}{2}\)
\(=\)\(\left[\left(31.32.33....60\right)\right]\)\(.\)\(\left(\frac{1.2.3....30}{2^{30}}\right)\)\(.\)\(\left(1.2.3....30\right)\)
\(=\)\(\left[\frac{\left(1.3.5....59\right).\left(2.4.6....60\right)}{2.4.6....60}\right]\)\(=\)\(1.3.5....59\)
Vậy \(\frac{31}{2}\)\(.\)\(\frac{32}{2}\)\(.\)\(\frac{33}{2}\)\(....\)\(\frac{60}{2}\)\(=\)\(1.3.5....59\)
ta có:Đặt A= \(1.3.5.....59=\frac{1.2.3.4.....59.60}{2.4.6.....60}\)
=\(\frac{1.2.3.....59.60}{2^{30}.\left(1.2.3.....30\right)}=\frac{31.32.....59.60}{2^{30}}\)
= \(\frac{31}{2}.\frac{32}{2}.....\frac{59}{2}.\frac{60}{2}\)
vì \(\frac{31}{2}.\frac{32}{2}.....\frac{59}{2}.\frac{60}{2}\) = \(\frac{31}{2}.\frac{32}{2}.....\frac{59}{2}.\frac{60}{2}\)
\(\Rightarrow\)A= \(\frac{31}{2}.\frac{32}{2}.....\frac{59}{2}.\frac{60}{2}\)
( Điều phải chứng minh)
toán nâng cao lớp 6 đấy bạn nha
Chứng tỏ \(\frac{31}{2}\cdot\frac{32}{2}\cdot...\cdot\frac{60}{2}\)= 1.3.5.....59
\(1.3.5.7.9...59=\frac{\left(1.3.5...59\right).\left(2.4.6...60\right)}{2.4.6...60}=\frac{1.2.3...60}{2^{30}\left(1.2.3...30\right)}\)
\(=\frac{31.32.33...60}{2.2.2...2}=\frac{31}{2}\cdot\frac{32}{2}\cdot\frac{33}{2}...\frac{60}{2}\)
Vậy \(\frac{31}{2}\cdot\frac{32}{2}\cdot\frac{33}{2}...\frac{60}{2}=1.3.5...59\)(đpcm)
So sánh \(P=\frac{31}{2}.\frac{32}{2}.\frac{33}{2}...\frac{60}{2}\) và Q=1.3.5.7........59
Ta có:
31/2.32/2.33/2....60/2=31.32......60/2^30
=(31.32.33....60)(1.2.3....30)/2^30(1.2.3...30)
=(1.3.5...59)(2.4.6...60)/(2.4.6...60)=1.3.5...59
=>P=Q
nhớ ****
cái dòng 3, 4 mk ko hiểu sao 2^30.(1.2.3....30) lại bằng 2.4.6...60