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For each of the following, determine if substitution can be used to evaluate the integral. If so, fill in the substitution variable $w$ and the value of the integral; if not, enter na for both $w$ and the antiderivative.

integral	evaluates to	$w=$
$\int\,{\cos(x)\over 2+\sin(x)}\,dx =$
$\int\,{\cos(x)\over 2+\cos(x)}\,dx =$
$\int\,{x^{3}\over (2 + x^{4})^{2}}\,dx =$
$\int\,x^{3} \cos(x^{4})\,dx =$

You can earn partial credit on this problem.