If f(x) = (1 + x) (1+x2)(1+x3), then f'(1) =
20
24
28
32
f(x)=(1+x)(1+x2)(1+x3)
f′(x)=(1+x)(1+x2)3x2+(1+x)(1+x3).2x+(1+x2)(1+x3)
f′(1)=12+8+4=24