ln(1+x) =x-x²/2+x³/3+……+(-1)^(n-1) * x^n/n+...x=0LS=ln1=0RS = 0
1+C(a,1)x+C(a,2)x²+C(a,3)x³+....=1+ax+a(a-1)/2! x²+a(a-1)(a-2)/3! x³+......
