Hi, IM having trouble with this topic..this is probly all wrong, but any help would be appreciated:(adsbygoogle = window.adsbygoogle || []).push({});

[tex]\int_{0}^{1} \sqrt{x^2 +1}dx[/tex]

so let

x=tanØ

dx=sec^2Ø

[tex]\sqrt{x^2+1} = \sqrt{tan^2Ø+ 1} = sec^2Ø[/tex]

when x=0 tanØ = 0 so tanØ = 0

when x=1 tanØ =[tex]\frac{\pi}{4}[/itex]

let u= cosØ

du=-sinØ

[tex]\int_{0}^{\frac{\pi}{4}} sec^2ØdØ[/tex]=

[tex]\int_{0}^{\frac{\pi}{4}} \frac{1}{cos^2Ø}dØ[/tex]=

[tex]-\int_{0}^{\frac{\pi}{4}} \frac{du}{u^2}dØ[/tex]

when Ø = 0 u = 1

when Ø = pi/4, u=root2/2

..i end up with an answer of 1-(root2/2)

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# Trig sub

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