exo7 1240

$\ln \cos x$ $n = 6$ $a = 0$.

$\dfrac{\arctan x -x}{\sin x -x}$ $n = 2$ $a = 0$.

$\ln \tan (\frac x2 + \frac{\pi}4)$ $n = 3$ $a = 0$.

$\ln \sin x$ $n = 3$ $a = \frac{\pi}4$.

$\sqrt[3]{x^3 + x}-\sqrt[3]{x^3-x}$ $n = 4$ $a = + \infty$.

$(1 + x)^{\frac 1x}$ $n = 3$ $a = 0$.

$x (\sqrt{x^2 + \sqrt{x^4 + 1}}-x\sqrt 2)$ $n = 2$ $a = + \infty$.