đặt $t=x^{2012} (t\geq 0)$PT Trở Thành:
$\sin t\pm \cos t=\frac{1}{2^{2015}}\Leftrightarrow \sin (t\pm \frac{\pi }{4})=\frac{1}{\sqrt{2}.2^{2015}}=a$
$\Leftrightarrow t\pm \frac{\pi }{4}=\arcsin a+k2\pi \vee t\pm \frac{\pi }{4}=\pi -\arcsin a+k2\pi (k\in Z)$
$\Leftrightarrow t=\pm \frac{\pi }{4}+\arcsin a+k2\pi \vee t\doteq \pm \frac{\pi }{4}+\pi -\arcsin a+k2\pi (k\in Z)$