A bit stuck on 5 and the second half of 6, I keep getting 1/4 for the coefficent of x^2 in 5. Thanks
How is that helping prove that the approx expansion is: 1+x+(1\2)x^2?
I had sqrt((1+x)/(1-x)) = ((1+x)^(1/2))*((1-x)^(-1/2))
I expanded those up to x^1 and got (1+(1/2)x)*(1+(1/2)x) using the binomial theorem, then that expands to 1+x+(1/4)x^2, very close to the answer, wondering if the book got it wrong..