Find limits of sine and cosine functions

Glissando
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Homework Statement


Find the limit:

lim (1-cos2x)/(xsinx)
x->0


Homework Equations


Identities


The Attempt at a Solution



I've done this over and over and over again! The answer is supposed to be 0 but I keep getting 2 ):

lim (1-cos2x)/(xsinx)
x->0

lim (1-1+2sin2x)/(xsinx)
x->0

lim (2sin2x)/(xsinx)
x->0

lim (2sinx)/x
x->0

= 2*1 = 2

Any help is appreciated! Thank you!
 
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I don't see anything wrong with what you did. I'd say the limit is 2 as well.
 
Thanks guys (: I guess textbook error then! Yay!

Thank you <3
 
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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