Let's name the first number x and the next number x + 1. So,
x^2 - (x + 1)^2
= x^2 - (x^2 + 2x + 1)
= x^2 - x^2 - 2x - 1
= - 2x - 1
= -(2x + 1)
Thus we can say that, the difference between the squares of two consecutive numbers is equal to the opposite of their sum (means it is their sum, but as a negative number).
Let's do some examples:
2, 3; 2 + 3 = 5
2^2 - 3^2 = 4 - 9 = -5 ( 5 and -5 are opposite numbers, and 5 is the sum of 2 and 3)
13, 14; 13 + 14 = 27
13^2 - 14^2 = 169 - 196 = -27 (27 and -27 are opposite numbers, and 27 is the sum of 13 and 14)
Just check the squares of a few whole numbers. If 55 is between two of those squares, then its square root is also between the corresponding square roots.
The numbers are 13 and 14.
3 and 5
7 and 9 72+92 = 130
The numbers are 12 and 14.
The difference between the squares of two consecutive integers j and j+1 is |2j+1|. There are therefore two such pairs where this quantity is 17:-9 and -88 and 9
There are no three consecutive numbers that are squares. Otherwise, there are an infinite sets of squares of three consecutive numbers: for example, {1,4,9}, or {4,9,16} or {576, 625, 676}
Difference between the sum of the squares and the square of the sums of n numbers?Read more:Difference_between_the_sum_of_the_squares_and_the_square_of_the_sums_of_n_numbers
16,25,36 add to 77. They are the squares of consecutive numbers 4,5,6
Just check the squares of a few whole numbers. If 55 is between two of those squares, then its square root is also between the corresponding square roots.
The numbers are (x) and (x+2).Their squares are (x)2 and (x+2)2, or (x2) and (x2 + 4x + 4).The difference between the squares is (x2 + 4x + 4) - (x2) = 4x + 4 = 484x + 4 = 48x + 1 = 12x = 11 and (x + 2) = 13======================Check:112 = 121132 = 169169 - 121 = 48 yay!
The numbers are 13 and 14.
5
8
5
15 and 16
17 and 18