-
ev
็ดน
(ไพ้ก)
29
้่ค็ตๅใใฎๅบๆฌ
ๆฌกใฎๅใใซ็ญใใใ ใใ ใ, ๅซใพใใชใๆฐๅญใๆๅญใใใฃใฆใใใใ
ใจใใไฝใใใ็ตใฎ็ทๆฐใๆฑใใใ
00000
(1) 1, 2, 3, 4 ใฎ4ๅใฎๆฐๅญใใ้่คใ่จฑใใฆ3ๅใฎๆฐๅญใๅใๅบใใ ใใฎ
(2) x, y, zใฎ3็จฎ้กใฎๆๅญใใไฝใใใ8ๆฌกใฎ้
ใฏไฝ้ใใงใใใใ
& SOLUTION
CHART L
้่ค็ตๅใ โใจไปๅใใฎๆดป็จ
p.294 ๅบๆฌไบ้
3
ใจ้้ใใใใใ ๆฌกใฎใใใซ,โใจไปๅใใซใใ้ ๅใจใใฆ่ใใๆนใ็ขบๅฎใงใใใ
(1) ็ฐใชใ4ๅใฎๆฐๅญใใ้่คใ่จฑใใฆ3ๅใฎๆฐๅญใๅใๅบใใ
p.294 ๅบๆฌไบ้
3 ใง็คบใใ Hr = n+r-1Cr ใ็ดใกใซไฝฟ็จใใฆใใใใใๆ
ฃใใชใใใกใฏ
3ๅใฎโใจ3ๅใฎไปๅใใฎ้ ๅ
โ
ไพใใฐใใใ||
1 2 3 4
1 2 3 4
ใฏ11ๅ 22ๅใ่กจใใ
ใใใใฏ2ใ1ๅ 31ๅ 41ๅใ่กจใใ
(2)็ฐใชใ3ๅใฎๆๅญใใ้่คใ่จฑใใฆ 8ๅใฎๆๅญใๅใๅบใใ
8ๅใฎโใจ2ๅใฎไปๅใใใฎ้ ๅ
ไพใใฐใใใ
x y z
8ๆฌกใฎ้
xyz ใ่กจใใ
ไธใใใใใฏxใ3ๅ, yใ1ๅ, zใ4ๅๅใฃใๅ ดๅใง,
303
1็ซ
3
็ตๅใ
ๆฐ่จ
ๅผ
็ญ
(1)3ๅใฎโใจ3ๅใฎใฎ้ ๅใฎ็ทๆฐใๆฑใใๅ ดๅใฎๆฐใจใช
6.5.4
ใใใ
6C3=
-=20 (้ใ)
3.2.1
ๆฑใใ็ตใฎ็ทๆฐใฏ,4็จฎ้กใฎๆฐๅญใใ้่คใ่จฑใใฆ3
(+S) ++
ๅๅใๅบใ็ตๅใใฎ็ทๆฐใซ็ญใใใใ
4H3=4+3-1C3=6C3=20 (้ใ)FOX
(2)8ๅใฎโใจ2ๅใฎใฎ้ ๅใฎ็ทๆฐใๆฑใใๅ ดๅใฎๆฐใจใช
ใใใ
10.9
10C8=10C2= -=45 (้ใ)
2.1
3Hs=3+8โ1Cg=10C8=10C2=45 (้ใ)
โ 6ๅใฎๅ ดๆใใโใ็ฝฎ
ใ3ๅใฎๅ ดๆใ้ธใถ็ท
ๆฐใใใใฏ,ๅใใใฎใ
ๅซใ้ ๅใฎ็ทๆฐใงใใ
6!
3!3!
-=20 ใงใใใใ
โnHr=n+r-1Cr
โ
10!
-=45 ใงใใใใ
2!8!
PRACTICE 29 3
โข
(1)8ๅใฎใใใใA,B,C,D ใฎ 4 ใคใฎ่ขใซๅใใๆนๆณใฏไฝ้ใใใใใใใ ใ,
1ๅใๅ
ฅใใชใ่ขใใใฃใฆใใใใใฎใจใใใ
(2)(x+y+z)ใฎๅฑ้ๅผใฎ็ฐใชใ้
ใฎๆฐใๆฑใใใ