Show that the square of an odd positive
Integers can be of the form 6q+1 or 6q +3
for some integer q
Answers
Answer:
We know that any positive integer can be of the form 6m, 6m + 1, 6m + 2, 6m + 3, 6m + 4 or 6m + 5, for some integer m.
Thus, an odd positive integer can be of the form 6m + 1, 6m + 3, or 6m + 5
Thus we have:
(6 m +1)2 = 36 m2 + 12 m + 1 = 6 (6 m2 + 2 m) + 1 = 6 q + 1,
q is an integer
(6 m + 3)2 = 36 m2 + 36 m + 9 = 6 (6 m2 + 6 m + 1) + 3 = 6 q + 3,
q is an integer
(6 m + 5)2 = 36 m2 + 60 m + 25 = 6 (6 m2 + 10 m + 4) + 1 = 6 q + 1,
q is an integer.
Thus, the square of an odd positive integer can be of the form 6q + 1 or 6q + 3.
let a be any positive integer
then
b=5
0≤r<b
0≤r<6
r=0,1,2, 3,4, 5
case 1.
r=0
a=bq+r
6q+0
(6q)^2
36q^2
6(6q^2)
let 6q^2 be m
=6m
case 2.
r=1
a=bq+r
(6q+1)^2
(6q^2)+2*6q*1+1^2
36q^2+12q+1
6(6q^2+2q)+1
let 6q^2+2q be m
= 6m+1
case 3.
r=2
(6q+2)^2
36q^2+24q+4
6(6q^2+4q)+4
let 6q^2+4q be m
= 6m+4
case4.
r=3
(6q+3)^2
36q^2+36q+9
36q^2+36q+6+3
6(6q^2+6q+1)+3
let the 6q^2+6q+1 be m
= 6m+3
case 5.
r=4
(6q+4)^2
36q^2+48q+16
36q^2+48q+12+4
6(6q^2+8q+2)+4
let 6q^2+8q+4 be m
6m+4
case 6
r=5
(6q+5)^2
36q^2+60q+24+1
6(6q^2+10q+4)+1
let 6q^2+10q+4 bem
= 6m+1