a and b are positive integers and a2−b2 is a prime number. Since, a2−b2=(a+b)(a−b) product of two numbers. ∴ Either a+b=1 or a−b=1 Case I : a+b=1⇒ Either a=0 or b=0 then a2−b2=1 or −1 which is not a prime number. ∴ This case is not possible Case II : a−b=1→a and b can be taken anything with b<a. ln this case a2−b2=a+b is a prime number. ∴a2−b2=a+b.
The binomial theorem formula is used in the expansion of any power of a binomial in the form of a series. The binomial theorem formula is
Properties of Binomial Theorem
The number of coefficients in the binomial expansion of (x + y)n is equal to (n + 1).
There are (n+1) terms in the expansion of (x+y)n.
The first and the last terms are xn and yn respectively.
From the beginning of the expansion, the powers of x, decrease from n up to 0, and the powers of a, increase from 0 up to n.
The binomial coefficients in the expansion are arranged in an array, which is called Pascal's triangle. This pattern developed is summed up by the binomial theorem formula.