If f(x)=x4+3x2−6x−2  then the coefficient of x3  in f(x+1)  is

The given equation is f(x)=x4+3x2−6x−2 Now,f(x+1)=(x+1)4+3(x+1)2−6(x+1)−2 Consider (x+1)4 for the coefficient of x3  =(x+1)2(x+1)2=(x2+2x+1)(x2+2x+1) =x4+4x3+7x2+6x+2 ∴  the coefficient of x3=4