$\left(c+b\right).a$

$x+3\sqrt{-\frac{1}{3}^x}$

$\lim\:_{a\to\:\:0}\left(\frac{\sin\:^3\left(a\right)}{\sin\:\left(a\right)-\tan\:\left(a\right)}\right)$

$2d-6d$

$e^{-\infty^2}$

$\left(3+n\right).\left(6+m\right)$

$y=\:\:\frac{1}{2}\:sen\:\left(2\pi x\right)+\:\:\frac{1}{4}\:sen\left(4\pi x\right)$