Two Pwr Series Questions- relatively simple

  • Thread starter Thread starter asif zaidi
  • Start date Start date
  • Tags Tags
    Series
asif zaidi
Messages
56
Reaction score
0
Hello:
(at least I think they are simple !)

The 1st question is not a h/w problem. It is a question from textbook
The 2nd question is a h/w problem.

Problem1:
The series for log(1+x) is proven -1<x<=1. It then says the Taylor Series for (1/x)log(1+x) follows.
Do they mean that the individual components of log(1+x) will be multiplied by (1/x). If true, would this apply for x, x^2 etc...

Problem2:
Put e=exp(1). Use the Taylor Series expansion of exp to compute e.

Solution
When I solve this, I can get the TS for exp. Do I have to evaluate it at x=1?

Thanks

Asif
 
Physics news on Phys.org
For the first one, if by components you mean power series terms, yes. For the second, yes, you have to put x=1 in. How many terms you need to keep depends on the accuracy of the answer you need. You'll need a taylor series remainder term if you need to be rigorous about it.
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
Back
Top