SOLUTION: Help pls 😊 Triangular numbers are: 1,3,6,10....where the nth such number is n(n-1)/2. Show that the sum of two consecutive triangular numbers is a square number.

Question 985848: Help pls 😊
Triangular numbers are: 1,3,6,10....where the nth such number is n(n-1)/2. Show that the sum of two consecutive triangular numbers is a square number.
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
Triangular numbers are: 1,3,6,10....where the nth such number is n(n-1)/2. Show that the sum of two consecutive triangular numbers is a square number.
------------
n(n-1)/2 + (n+1)*n/2 = (n^2-n + n^2+n)/2
= 2n^2/2
= n^2
RELATED QUESTIONS
Show that the sum of nth term of the series log3+log6+log12+.... Is... (answered by richard1234,Edwin McCravy)

I've got this problem (see below). I've worked through problems 1b - 1d, but I am stuck... (answered by stanbon)

Three lockers are numbered consecutively (n,n+1,n+2) in such a way that the sum of the... (answered by )

Three lockers are numbered consecutively (n,n+1,n+2) in such a way that the sum of the... (answered by ewatrrr)

find three consecutive whole numbers such that the sum of the first two numbers equals... (answered by Theo)

did I do this right: Use the geometric sequence of numbers 1, 3, 9, 27, � to find the... (answered by fractalier)

Please help me solve the following problems. I've tried to solve the problem but I don't (answered by venugopalramana)

THE SUM OF THE SQUARES OF TWO CONSECUTIVE POSITIVE INTEGERS IS 41 41=n^2(n+1)^2... (answered by richard1234)

Find the number of bases n \ge 2$ such that 100_n + 1_n is... (answered by math_tutor2020,ikleyn)

SOLUTION: Help pls &#128522; Triangular numbers are: 1,3,6,10....where the nth such number is n(n-1)/2. Show that the sum of two consecutive triangular numbers is a square number.

SOLUTION: Help pls 😊 Triangular numbers are: 1,3,6,10....where the nth such number is n(n-1)/2. Show that the sum of two consecutive triangular numbers is a square number.