Question

Let $y (x)=(1+x)\left(1+x^2\right)\left(1+x^4\right)\left(1+x^8\right)\left(1+x^{16}\right)$ Then $y^{\prime}-y^{\prime \prime}$ at $x=-1$ is equal to :

• A. 976
• B. 944
• C. 496
• D. 464

Answer 1

Answer: (C)

496

Answer 2

y=1-x1-x32??y-xy=1-x32
y'-xy'-y=-32x31
y''-xy''-y'-y'=-(32)(31)x30
at x=-1?y'-y''=496