Results related to Binomial Coefficieints

1. Coefficient of (r+1)th term in the binomial expression of (1+x)ⁿ is ⁿC_r

2. Coefficient of x^r in the binomial expression of (1+x)ⁿ is ⁿC_r
3. 1. Coefficient of (r+1)th term in the binomial expression of (1-x)ⁿ is (-1)^rnC_r


4. Coefficient of x^r in the binomial expression of (1-x)ⁿ is (-1)^rnC_r