WBJEE · Maths · Differentiation
If \(y=(1+x)\left(1+x^2\right)\left(1+x^4\right) \ldots\left(1+x^{2 n}\right)\) then the value of \(\left(\frac{d y}{d x}\right)_{x=0}\) is
- A 0
- B -1
- C 1
- D 2
Answer & Solution
Correct Answer
(C) 1
Step-by-step Solution
Detailed explanation
Hints: T-log \& Differentiate \[ \begin{aligned} & \frac{d y}{d x}=y\left[\frac{1}{1+x}+\frac{2 x}{1+x^2}+\ldots\right] \text { Put } x=0 \\ & \frac{d y}{d x}=1 \end{aligned} \]
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