Calculating Limits: Need Help Solving These!

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Hi

I´m new here and i´m new on this course. I have a test tomorrow and i need to know how to calculate limits, but i have some that i can´t solve, please can you solve it, ins´t homework, it´s only to learn (don´t use l'hospital):

lim | x | / (x + 1)
x->0


lim (1 + sin x)^(1/x)
x->0


lim (e^(2 sin x) - e^(sin x)) / (sin 2x)
x->0


Thanks in advance
 
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lim | x | / (x + 1)
x->0

Show the function is continuous at 0
limit of a continuous function is an evaluation

lim (1 + sin x)^(1/x)
x->0

rewrite as

lim (1 + x[sin x/x])^(1/x)
x->0
use
lim (1 + x*a)^(1/x)=exp(a)
x->0
and composition or squish theorem

lim (e^(2 sin x) - e^(sin x)) / (sin 2x)
x->0

rewrite as
lim (e^(2 y) - e^y) / y
y->sin(x)->0

and

(e^(2 y) - e^y)=(e^y-1)^2+(e^y-1)

and

lim (e^x- 1) / x=1
x->0
 
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...
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