Finding Limit of x as it Approaches 0

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Homework Statement


find:
lim x\rightarrow0 (x+2)tan-1(x+2)-xtan-1(x)


Homework Equations





The Attempt at a Solution


lim x\rightarrow0 (x+2)tan-1(x+2)-xtan-1(x)=
lim x\rightarrow0 [x(tan-1(x+2)-tan-1(x))+2tan-1(x+2)]
 
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pcm said:

Homework Statement


find:
lim x\rightarrow0 (x+2)tan-1(x+2)-xtan-1(x)


Homework Equations





The Attempt at a Solution


lim x\rightarrow0 (x+2)tan-1(x+2)-xtan-1(x)=
lim x\rightarrow0 [x(tan-1(x+2)-tan-1(x))+2tan-1(x+2)]

Your functions are all continuous. What happens if you plug in ##x=0##?
 
ah sorry, its x\rightarrow∞
 
x(tan-1(x+2)-tan-1(x))
this part can be evaluated using l hopital(?),but it requires multiple use of rule.
i am expecting kind of trigonometric solution.
 
Focus on the tan-1(x) and tan-1(x+2). What are their limits as x goes to infinity?
 
both tends to π/2
 
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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