If y = (1+x)(1+x^2)(1+x^4) (1+x^ 2^n ) then dy dx at x=0 is

JEE Advanced Mathematics question

If then at is

Answer: (A)

Multiply and divide by ; the product telescopes because , , and so on:

y = = .

By the quotient rule,

= {--x) +

Create a free account to read the complete working (6 steps), and practise questions like this in a timed test.

Question ID VK-109203