heres what i have:(adsbygoogle = window.adsbygoogle || []).push({});

[tex] \int_{0}^{2\sqrt{3}} \frac {x^3}{\sqrt{16-x^2}}dx[/tex]

let [tex]x=4sin\phi[/tex]

[tex]dx=4cos4\phi[/tex]

[tex]\sqrt{16-x^2} = \sqrt{16-4sin^2\phi} = \sqrt{4cos^2\phi = 4cos\phi[/tex]

[tex]\int_{0}^{2\sqrt{3}} \frac{x^3}{\sqrt{16-x^2}}dx[/tex]

[tex]\int_{0}^{2\sqrt{3}} \frac{4sin^3\phi}{4cos\phi}4cos\phi d\phi[/tex]

[tex]= 4\int_{0}^{2\sqrt{3}} sin^3/phi [/tex]

[tex]=4\int_{0}^{2\sqrt{3}}sin^2\phi(sin(phi)[/tex]

[tex]=4\int_{0}^{2\sqrt{3}} 1-cos^2\phi(sin\phi)[/tex]

[tex]=4\int_{0}^{2\sqrt{3}} sin\phi - sin \phi (cos^2\phi) [/tex]

this is as far as i went because i think i messed up

any help would be appreciated

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# Homework Help: Another trig sub problem

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