$\frac{d^2}{dx^2}\left(x\cdot\cos\left(x\right)\right)b$

$3x^2dx+ydy=0$

$\lim_{x\to\infty}\left(\sin\left(\sqrt{1+x}\right).\sin\left(\sqrt{x}\right)\right)$

$2\left(\frac{1}{4x^{\frac{3}{4}}}\right)\left(\frac{1}{4x^{\frac{5}{4}}}\right)$

$3a+2a^2$

$5673\sqrt{704}$

$16t^2-40t+25$